2009 |
Periyasamy, Ganga ; Sour, Angelique ; Collin, Jean-Paul ; Sauvage, Jean-Pierre ; Remacle, Francoise Computational, Structural, and Mechanistic Analysis of the Electrochemically Driven Pirouetting Motion of a Copper Rotaxane Journal Article In: JOURNAL OF PHYSICAL CHEMISTRY B, 113 (18), pp. 6219–6229, 2009, ISSN: 1520-6106. @article{periyasamy_computational_2009, title = {Computational, Structural, and Mechanistic Analysis of the Electrochemically Driven Pirouetting Motion of a Copper Rotaxane}, author = {Periyasamy, Ganga and Sour, Angelique and Collin, Jean-Paul and Sauvage, Jean-Pierre and Remacle, Francoise}, doi = {10.1021/jp901214b}, issn = {1520-6106}, year = {2009}, date = {2009-05-01}, journal = {JOURNAL OF PHYSICAL CHEMISTRY B}, volume = {113}, number = {18}, pages = {6219--6229}, abstract = {A mechanism for the electrochemically driven reorganization of a model copper [2]pseudorotaxane is proposed on the basis of density functional theory computations and validated by comparing to experimental results. We investigate in detail the ligand reorganization around the Cu ion from a 4 to 5 coordination number that follows the conversion of the oxidation state from +1 to +2. It is found that for both the oxidation and the reduction processes the rearrangement proceeds in a concerted fashion via a single transition state. Energy paths involving stable decoordinated-coordinated intermediates are computed to be higher in energy. The cyclic voltammogram simulated using the computed transition theory state rate constants in solvent medium is in good agreement with the experimental voltammogram. Further, we report on the computed concentration change of stable (Cu-4(+), Cu-5(2+)) and metastable species (Cu-4(2+), Cu-5(+)) during single cyclic voltammetry (CV) cycle as a function of the applied voltage or time (the subscripts 4 and 5 refer to the coordination number of the copper center).}, keywords = {}, pubstate = {published}, tppubtype = {article} } A mechanism for the electrochemically driven reorganization of a model copper [2]pseudorotaxane is proposed on the basis of density functional theory computations and validated by comparing to experimental results. We investigate in detail the ligand reorganization around the Cu ion from a 4 to 5 coordination number that follows the conversion of the oxidation state from +1 to +2. It is found that for both the oxidation and the reduction processes the rearrangement proceeds in a concerted fashion via a single transition state. Energy paths involving stable decoordinated-coordinated intermediates are computed to be higher in energy. The cyclic voltammogram simulated using the computed transition theory state rate constants in solvent medium is in good agreement with the experimental voltammogram. Further, we report on the computed concentration change of stable (Cu-4(+), Cu-5(2+)) and metastable species (Cu-4(2+), Cu-5(+)) during single cyclic voltammetry (CV) cycle as a function of the applied voltage or time (the subscripts 4 and 5 refer to the coordination number of the copper center). |
Laux, E; Genet, C; Ebbesen, T W Enhanced optical transmission at the cutoff transition Journal Article In: OPTICS EXPRESS, 17 (9), pp. 6920–6930, 2009, ISSN: 1094-4087. @article{laux_enhanced_2009, title = {Enhanced optical transmission at the cutoff transition}, author = {Laux, E. and Genet, C. and Ebbesen, T. W.}, doi = {10.1364/OE.17.006920}, issn = {1094-4087}, year = {2009}, date = {2009-04-01}, journal = {OPTICS EXPRESS}, volume = {17}, number = {9}, pages = {6920--6930}, abstract = {The phenomenon of extraordinary transmission in the optical regime for circular hole arrays in optically thick metal films is studied as a function of hole size and depth. In the limit of small holes compared to the depth, the transmission properties follow a waveguide type behavior. By describing the transmission process as resulting from the interference between a resonant and a non-resonant contribution, a transition is clearly revealed through the specific spectral variations of the resonance at a given hole depth. This transition is associated to a change in the attenuation through the hole as its size increases, and corresponds to the optimal condition for surface plasmon excitation. (C) 2009 Optical Society of America}, keywords = {}, pubstate = {published}, tppubtype = {article} } The phenomenon of extraordinary transmission in the optical regime for circular hole arrays in optically thick metal films is studied as a function of hole size and depth. In the limit of small holes compared to the depth, the transmission properties follow a waveguide type behavior. By describing the transmission process as resulting from the interference between a resonant and a non-resonant contribution, a transition is clearly revealed through the specific spectral variations of the resonance at a given hole depth. This transition is associated to a change in the attenuation through the hole as its size increases, and corresponds to the optimal condition for surface plasmon excitation. (C) 2009 Optical Society of America |
Maragakis, Paul ; van der Vaart, Arjan ; Karplus, Martin Gaussian-Mixture Umbrella Sampling Journal Article In: JOURNAL OF PHYSICAL CHEMISTRY B, 113 (14), pp. 4664–4673, 2009, ISSN: 1520-6106. @article{maragakis_gaussian-mixture_2009, title = {Gaussian-Mixture Umbrella Sampling}, author = {Maragakis, Paul and van der Vaart, Arjan and Karplus, Martin}, doi = {10.1021/jp808381s}, issn = {1520-6106}, year = {2009}, date = {2009-04-01}, journal = {JOURNAL OF PHYSICAL CHEMISTRY B}, volume = {113}, number = {14}, pages = {4664--4673}, abstract = {We introduce the Gaussian-mixture umbrella sampling method (GAMUS), a biased molecular dynamics technique based on adaptive umbrella sampling that efficiently escapes free energy minima in multidimensional problems. The prior simulation data are reweighted with a maximum likelihood formulation, and the new approximate probability density is fit to a Gaussian-mixture model, augmented by information about the unsampled areas. The method can be used to identify free energy minima in multidimensional reaction coordinates. To illustrate GAMUS, we apply it to the alanine dipeptide (2D reaction coordinate) and tripeptide (4D reaction coordinate).}, keywords = {}, pubstate = {published}, tppubtype = {article} } We introduce the Gaussian-mixture umbrella sampling method (GAMUS), a biased molecular dynamics technique based on adaptive umbrella sampling that efficiently escapes free energy minima in multidimensional problems. The prior simulation data are reweighted with a maximum likelihood formulation, and the new approximate probability density is fit to a Gaussian-mixture model, augmented by information about the unsampled areas. The method can be used to identify free energy minima in multidimensional reaction coordinates. To illustrate GAMUS, we apply it to the alanine dipeptide (2D reaction coordinate) and tripeptide (4D reaction coordinate). |
Piot, Luc ; Palma, Carlos-Andres ; Llanes-Pallas, Anna ; Prato, Maurizio ; Szekrenyes, Zsolt ; Kamaras, Katalin ; Bonifazi, Davide ; Samori, Paolo Selective Formation of Bi-Component Arrays Through Ħ-Bonding of Multivalent Molecular Modules Journal Article In: ADVANCED FUNCTIONAL MATERIALS, 19 (8), pp. 1207–1214, 2009, ISSN: 1616-301X. @article{piot_selective_2009, title = {Selective Formation of Bi-Component Arrays Through Ħ-Bonding of Multivalent Molecular Modules}, author = {Piot, Luc and Palma, Carlos-Andres and Llanes-Pallas, Anna and Prato, Maurizio and Szekrenyes, Zsolt and Kamaras, Katalin and Bonifazi, Davide and Samori, Paolo}, doi = {10.1002/adfm.200801419}, issn = {1616-301X}, year = {2009}, date = {2009-04-01}, journal = {ADVANCED FUNCTIONAL MATERIALS}, volume = {19}, number = {8}, pages = {1207--1214}, abstract = {Here, the formation of discrete supramolecular mono- and bi-component architectures from novel and multivalent molecular modules bearing complementary recognition moieties that are prone to undergo multiple H-bonds, such as 2,6-di(acetylamino)pyridine and uracil residues, is described. These nanostructured H-bonded arrays, including dimeric and pentameric species, are thoroughly characterized in solution by NMR, in the solid state by FT-IR, and at the solid-liquid interface by means of scanning tunneling microscopy. The employed strategy is extremely versatile as it relies on the tuning of the valency, size, and geometry of the molecular modules; thus, it may be of interest for the bottom-up fabrication of nanostructured functional materials with sub-nanometer precision.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Here, the formation of discrete supramolecular mono- and bi-component architectures from novel and multivalent molecular modules bearing complementary recognition moieties that are prone to undergo multiple H-bonds, such as 2,6-di(acetylamino)pyridine and uracil residues, is described. These nanostructured H-bonded arrays, including dimeric and pentameric species, are thoroughly characterized in solution by NMR, in the solid state by FT-IR, and at the solid-liquid interface by means of scanning tunneling microscopy. The employed strategy is extremely versatile as it relies on the tuning of the valency, size, and geometry of the molecular modules; thus, it may be of interest for the bottom-up fabrication of nanostructured functional materials with sub-nanometer precision. |
Palma, Carlos-Andres ; Bonini, Massimo ; Breiner, Thomas ; Samori, Paolo Supramolecular Crystal Engineering at the Solid-Liquid interface from First Principles: Toward Unraveling the Thermodynamics of 2D Self-Assembly Journal Article In: ADVANCED MATERIALS, 21 (13), pp. 1383–1386, 2009, ISSN: 0935-9648. @article{palma_supramolecular_2009, title = {Supramolecular Crystal Engineering at the Solid-Liquid interface from First Principles: Toward Unraveling the Thermodynamics of 2D Self-Assembly}, author = {Palma, Carlos-Andres and Bonini, Massimo and Breiner, Thomas and Samori, Paolo}, doi = {10.1002/adma.200802068}, issn = {0935-9648}, year = {2009}, date = {2009-04-01}, journal = {ADVANCED MATERIALS}, volume = {21}, number = {13}, pages = {1383--1386}, abstract = {The formation of highly ordered 2D supramolecular architect assembled at the solid-solution interfaces is subject to complex interactions between the analytes, the solvent, and the substrate. These for have to be mastered in order to regard self-assembly as an effective bottom-up approach for functional-device engineering. At such interfaces, prediction of the thermodynamics governing the formation of spatially ordered 2D arrangements is far from being fully understood, even for the physisorption of a single molecular component on the basal plane of a flat surface. Two recent contributions on controlled polymorphism and nanopattern formation render it possible to gain semi-quantitative insight into the thermodynamics of physisorption at interfaces, paving the way towards 2D supramolecular crystal engineering. Although in these two works different systems have been chosen to tackle such a complex task, authors showed that the chemical design of molecular building blocks is not the only requirement to fulfill when trying to preprogram self-assembled patterns at the solid-liquid interface.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The formation of highly ordered 2D supramolecular architect assembled at the solid-solution interfaces is subject to complex interactions between the analytes, the solvent, and the substrate. These for have to be mastered in order to regard self-assembly as an effective bottom-up approach for functional-device engineering. At such interfaces, prediction of the thermodynamics governing the formation of spatially ordered 2D arrangements is far from being fully understood, even for the physisorption of a single molecular component on the basal plane of a flat surface. Two recent contributions on controlled polymorphism and nanopattern formation render it possible to gain semi-quantitative insight into the thermodynamics of physisorption at interfaces, paving the way towards 2D supramolecular crystal engineering. Although in these two works different systems have been chosen to tackle such a complex task, authors showed that the chemical design of molecular building blocks is not the only requirement to fulfill when trying to preprogram self-assembled patterns at the solid-liquid interface. |
Treossi, Emanuele ; Liscio, Andrea ; Feng, Xinliang ; Palermo, Vincenzo ; Muellen, Klaus ; Samori, Paolo Large-area bi-component processing of organic semiconductors by spray deposition and spin coating with orthogonal solvents Journal Article In: APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 95 (1, SI), pp. 15–20, 2009, ISSN: 0947-8396. @article{treossi_large-area_2009, title = {Large-area bi-component processing of organic semiconductors by spray deposition and spin coating with orthogonal solvents}, author = {Treossi, Emanuele and Liscio, Andrea and Feng, Xinliang and Palermo, Vincenzo and Muellen, Klaus and Samori, Paolo}, doi = {10.1007/s00339-009-5123-4}, issn = {0947-8396}, year = {2009}, date = {2009-04-01}, journal = {APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING}, volume = {95}, number = {1, SI}, pages = {15--20}, abstract = {Micrometre-thick uniform layers of a polymeric semiconductor (poly(3-hexylthiophene), P3HT) have been fabricated from solution by spray deposition making use of a commercial airbrush. Multi-scale characterization by optical microscopy and atomic force microscopy revealed the formation of smooth layers featuring reproducible patterns of spatially correlated micron-sized holes. This morphology was found to be uniform over the whole sample surface, on millimetre scale. On this micro-patterned P3HT layer an orthogonal solvent (i.e. a solvent which does not dissolve the P3HT) has been employed to deposit either by spin coating or by drop casting a second organic semiconductor. While spin-coated films exhibited nano-crystals of an alkylated perylene tetracarboxy diimide (PDI) preferentially grown into the micro-fabricated holes, drop-cast films displayed crystalline PDI fibres adsorbed on the patterned surface in random positions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Micrometre-thick uniform layers of a polymeric semiconductor (poly(3-hexylthiophene), P3HT) have been fabricated from solution by spray deposition making use of a commercial airbrush. Multi-scale characterization by optical microscopy and atomic force microscopy revealed the formation of smooth layers featuring reproducible patterns of spatially correlated micron-sized holes. This morphology was found to be uniform over the whole sample surface, on millimetre scale. On this micro-patterned P3HT layer an orthogonal solvent (i.e. a solvent which does not dissolve the P3HT) has been employed to deposit either by spin coating or by drop casting a second organic semiconductor. While spin-coated films exhibited nano-crystals of an alkylated perylene tetracarboxy diimide (PDI) preferentially grown into the micro-fabricated holes, drop-cast films displayed crystalline PDI fibres adsorbed on the patterned surface in random positions. |
Reutenauer, Philippe ; Boul, Peter J; Lehn, Jean-Marie Dynamic Diels-Alder Reactions of 9,10-Dimethylanthracene: Reversible Adduct Formation, Dynamic Exchange Processes and Thermal Fluorescence Modulation Journal Article In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, (11), pp. 1691–1697, 2009, ISSN: 1434-193X. @article{reutenauer_dynamic_2009, title = {Dynamic Diels-Alder Reactions of 9,10-Dimethylanthracene: Reversible Adduct Formation, Dynamic Exchange Processes and Thermal Fluorescence Modulation}, author = {Reutenauer, Philippe and Boul, Peter J. and Lehn, Jean-Marie}, doi = {10.1002/ejoc.200801269}, issn = {1434-193X}, year = {2009}, date = {2009-04-01}, journal = {EUROPEAN JOURNAL OF ORGANIC CHEMISTRY}, number = {11}, pages = {1691--1697}, abstract = {Studies of the Diels-Alder reactions between 9,10-dimethylanthracene and cyano-functionalized dienophiles led to the identification and characterization of new dynamic systems under ambient conditions. Among these dienophiles were tricyanoethynylethylene derivatives, which gave access to reversible thermal switching of fluorescent properties through binding to and release of the dimethylanthracene partner. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)}, keywords = {}, pubstate = {published}, tppubtype = {article} } Studies of the Diels-Alder reactions between 9,10-dimethylanthracene and cyano-functionalized dienophiles led to the identification and characterization of new dynamic systems under ambient conditions. Among these dienophiles were tricyanoethynylethylene derivatives, which gave access to reversible thermal switching of fluorescent properties through binding to and release of the dimethylanthracene partner. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) |
Collin, Jean-Paul ; Frey, Julien ; Heitz, Valerie ; Sauvage, Jean-Pierre ; Tock, Christian ; Allouche, Lionel Adjustable Receptor Based on a [3]Rotaxane Whose Two Threaded Rings Are Rigidly Attached to Two Porphyrinic Plates: Synthesis and Complexation Studies Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (15), pp. 5609–5620, 2009, ISSN: 0002-7863. @article{collin_adjustable_2009, title = {Adjustable Receptor Based on a [3]Rotaxane Whose Two Threaded Rings Are Rigidly Attached to Two Porphyrinic Plates: Synthesis and Complexation Studies}, author = {Collin, Jean-Paul and Frey, Julien and Heitz, Valerie and Sauvage, Jean-Pierre and Tock, Christian and Allouche, Lionel}, doi = {10.1021/ja900565p}, issn = {0002-7863}, year = {2009}, date = {2009-04-01}, journal = {JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, volume = {131}, number = {15}, pages = {5609--5620}, abstract = {The design and synthesis of a new type of receptor based on a [3]rotaxane, consisting of one thread and two threaded rings, is reported, as well as some of its complexing properties toward given guests. Two rings rigidly attached to porphyrins are threaded by a stiff rod incorporating two 2,2'-bipyridine-like chelates, the threading process being driven by two Cu(I) atoms acting as templates. A double-stoppering reaction based on click chemistry leads to the copper-complexed [3]rotaxane in which the rings are located close to the central part of the thread and the distance between the two porphyrin plates is short. Removal of the two Cu(I) cations releases the two rings which are now free to move along and around the thread. In these two states of the [3]rotaxane, free and complexed with copper, the two zinc(II) porphyrins attached to the rings can bind different ditopic guests bearing pyridyl groups or amines as terminal functions. UV-visible and NMR DOSY experiments were realized with guests of different sizes, and the association constants were determined. The free [3]rotaxane is both a strong and highly adaptable receptor with high stability constants for the host/guest complexes, log K being in the range of 6.3-7.5 for guests with a length varying between 2.8 and 18 angstrom. The copper-complexed [3]rotaxane is still a good receptor for small guests due to an entropic gain for this preorganized molecule compared to the free [3]rotaxane, but it is a less strong receptor for guests which do not fit the short distance between the two porphyrins.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The design and synthesis of a new type of receptor based on a [3]rotaxane, consisting of one thread and two threaded rings, is reported, as well as some of its complexing properties toward given guests. Two rings rigidly attached to porphyrins are threaded by a stiff rod incorporating two 2,2'-bipyridine-like chelates, the threading process being driven by two Cu(I) atoms acting as templates. A double-stoppering reaction based on click chemistry leads to the copper-complexed [3]rotaxane in which the rings are located close to the central part of the thread and the distance between the two porphyrin plates is short. Removal of the two Cu(I) cations releases the two rings which are now free to move along and around the thread. In these two states of the [3]rotaxane, free and complexed with copper, the two zinc(II) porphyrins attached to the rings can bind different ditopic guests bearing pyridyl groups or amines as terminal functions. UV-visible and NMR DOSY experiments were realized with guests of different sizes, and the association constants were determined. The free [3]rotaxane is both a strong and highly adaptable receptor with high stability constants for the host/guest complexes, log K being in the range of 6.3-7.5 for guests with a length varying between 2.8 and 18 angstrom. The copper-complexed [3]rotaxane is still a good receptor for small guests due to an entropic gain for this preorganized molecule compared to the free [3]rotaxane, but it is a less strong receptor for guests which do not fit the short distance between the two porphyrins. |
Volkov, Valentyn S; Bozhevolnyi, Sergey I; Rodrigo, Sergio G; Martin-Moreno, Luis ; Garcia-Vidal, Francisco J; Devaux, Eloise ; Ebbesen, Thomas W Nanofocusing with Channel Plasmon Polaritons Journal Article In: NANO LETTERS, 9 (3), pp. 1278–1282, 2009, ISSN: 1530-6984. @article{volkov_nanofocusing_2009, title = {Nanofocusing with Channel Plasmon Polaritons}, author = {Volkov, Valentyn S. and Bozhevolnyi, Sergey I. and Rodrigo, Sergio G. and Martin-Moreno, Luis and Garcia-Vidal, Francisco J. and Devaux, Eloise and Ebbesen, Thomas W.}, doi = {10.1021/nl900268v}, issn = {1530-6984}, year = {2009}, date = {2009-03-01}, journal = {NANO LETTERS}, volume = {9}, number = {3}, pages = {1278--1282}, abstract = {We investigate radiation nanofocusing with channel plasmon polaritons (CPPs) propagating along subwavelength metal grooves that are tapered synchronously in depth and in width. Efficient CPP nanofocusing at telecom wavelengths with the estimated field intensity enhancement of up to similar to 90 is directly demonstrated using near-field microscopy. Experimental observations are concurred with electromagnetic simulations, predicting the possibility of reaching the intensity enhancements of similar to 1200 and opening thereby exciting perspectives for practical applications of CPP nanofocusing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigate radiation nanofocusing with channel plasmon polaritons (CPPs) propagating along subwavelength metal grooves that are tapered synchronously in depth and in width. Efficient CPP nanofocusing at telecom wavelengths with the estimated field intensity enhancement of up to similar to 90 is directly demonstrated using near-field microscopy. Experimental observations are concurred with electromagnetic simulations, predicting the possibility of reaching the intensity enhancements of similar to 1200 and opening thereby exciting perspectives for practical applications of CPP nanofocusing. |
Samori, Paolo ; Cacialli, Franco ; Marletta, Giovanni ; Faria, Roberto ; Ruben, Mario Taming Complexity: From Supramolecules to Suprafunctions Journal Article In: ADVANCED MATERIALS, 21 (10-11), pp. 1037–1040, 2009, ISSN: 0935-9648. @article{samori_taming_2009, title = {Taming Complexity: From Supramolecules to Suprafunctions}, author = {Samori, Paolo and Cacialli, Franco and Marletta, Giovanni and Faria, Roberto and Ruben, Mario}, doi = {10.1002/adma.200900161}, issn = {0935-9648}, year = {2009}, date = {2009-03-01}, journal = {ADVANCED MATERIALS}, volume = {21}, number = {10-11}, pages = {1037--1040}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Ciesielski, Artur ; Piot, Luc ; Samori, Paolo ; Jouaiti, Abdelaziz ; Hosseini, Mir Wais Molecular Tectonics at the Solid/Liquid Interface: Controlling the Nanoscale Geometry, Directionality, and Packing of 1D Coordination Networks on Graphite Surfaces Journal Article In: ADVANCED MATERIALS, 21 (10-11), pp. 1131–1136, 2009, ISSN: 0935-9648. @article{ciesielski_molecular_2009, title = {Molecular Tectonics at the Solid/Liquid Interface: Controlling the Nanoscale Geometry, Directionality, and Packing of 1D Coordination Networks on Graphite Surfaces}, author = {Ciesielski, Artur and Piot, Luc and Samori, Paolo and Jouaiti, Abdelaziz and Hosseini, Mir Wais}, doi = {10.1002/adma.200801776}, issn = {0935-9648}, year = {2009}, date = {2009-03-01}, journal = {ADVANCED MATERIALS}, volume = {21}, number = {10-11}, pages = {1131--1136}, abstract = {Supramolecular arrays composed of 1D coordination networks on surfaces, with nanoscale control over both the geometry and the directionality, are achieved through the design and combination of organic tectons with metal complexes (CoCl2) or metal centers (Pd(BF4)(2)). Scanning tunneling microscope at the solid/liquid interface allows the visualization of long and shape-persistent arrays, with either linear or zig-zag geometries.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Supramolecular arrays composed of 1D coordination networks on surfaces, with nanoscale control over both the geometry and the directionality, are achieved through the design and combination of organic tectons with metal complexes (CoCl2) or metal centers (Pd(BF4)(2)). Scanning tunneling microscope at the solid/liquid interface allows the visualization of long and shape-persistent arrays, with either linear or zig-zag geometries. |
Ramirez, Juan ; Stadler, Adrian-Mihail ; Rogez, Guillaume ; Drillon, Marc ; Lehn, Jean-Marie Copper(II) Dinuclear Pyrazine-Based Rack-Type Complexes: Preparation, Structure, and Magnetic Properties Journal Article In: INORGANIC CHEMISTRY, 48 (6), pp. 2456–2463, 2009, ISSN: 0020-1669. @article{ramirez_copperii_2009, title = {Copper(II) Dinuclear Pyrazine-Based Rack-Type Complexes: Preparation, Structure, and Magnetic Properties}, author = {Ramirez, Juan and Stadler, Adrian-Mihail and Rogez, Guillaume and Drillon, Marc and Lehn, Jean-Marie}, doi = {10.1021/ic801675d}, issn = {0020-1669}, year = {2009}, date = {2009-03-01}, journal = {INORGANIC CHEMISTRY}, volume = {48}, number = {6}, pages = {2456--2463}, abstract = {A novel class of ditopic ligands, 1, was synthesized by the reaction of 2,5-pyrazine-dicarboxaldehyde with 2 equiv of acyl-/aroyl-hydrazine. Their structures were confirmed by 1D and 2D NMR and by X-ray crystallography. They gave heteroleptic Cu(II) dinuclear rack-like complexes of the formula [Cu(2)(terpy)(2)](OTf)(4), thus undergoing shape changes of significant amplitude. The solid-state structures of these complexes were determined by X-ray crystallography. The magnetic measurements performed on the complexes revealed the presence of antiferromagnetic intramolecular interactions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel class of ditopic ligands, 1, was synthesized by the reaction of 2,5-pyrazine-dicarboxaldehyde with 2 equiv of acyl-/aroyl-hydrazine. Their structures were confirmed by 1D and 2D NMR and by X-ray crystallography. They gave heteroleptic Cu(II) dinuclear rack-like complexes of the formula [Cu(2)(terpy)(2)](OTf)(4), thus undergoing shape changes of significant amplitude. The solid-state structures of these complexes were determined by X-ray crystallography. The magnetic measurements performed on the complexes revealed the presence of antiferromagnetic intramolecular interactions. |
Pace, Giuseppina ; Stefankiewicz, Artur ; Harrowfield, Jack ; Lehn, Jean-Marie ; Sarnori, Paolo Self-Assembly of Alkoxy-Substituted Bis(hydrazone)-Based Organic Ligands and of a Metallosupramolecular Grid on Graphite Journal Article In: CHEMPHYSCHEM, 10 (4), pp. 699–705, 2009, ISSN: 1439-4235. @article{pace_self-assembly_2009, title = {Self-Assembly of Alkoxy-Substituted Bis(hydrazone)-Based Organic Ligands and of a Metallosupramolecular Grid on Graphite}, author = {Pace, Giuseppina and Stefankiewicz, Artur and Harrowfield, Jack and Lehn, Jean-Marie and Sarnori, Paolo}, doi = {10.1002/cphc.200800733}, issn = {1439-4235}, year = {2009}, date = {2009-03-01}, journal = {CHEMPHYSCHEM}, volume = {10}, number = {4}, pages = {699--705}, abstract = {Self-assembly of a bis(hydrazone) chelating ligand functionalized with octadecyloxy substiturents is described, as well as the reproducible thermally activated self-assembly of its metallosupramolecular cationic Co-II [2x2] grid-type complex, on a highly oriented pyrolitic graphite (HOPG) substrate. Scanning tunnelling microscopy measurements at the solid/liquid interface reveal that the grid units of the annealed films ore oriented edge-on to the basal plane of the HOPG, which indicates that the influence of the octodecyl chains is not sufficient to tie the grids into a face-on orientation. To gain a detailed understanding of the self-assembly behaviour of the grid on HOPG, the results for the grid itself have been compared to those of its constituent ligands.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Self-assembly of a bis(hydrazone) chelating ligand functionalized with octadecyloxy substiturents is described, as well as the reproducible thermally activated self-assembly of its metallosupramolecular cationic Co-II [2x2] grid-type complex, on a highly oriented pyrolitic graphite (HOPG) substrate. Scanning tunnelling microscopy measurements at the solid/liquid interface reveal that the grid units of the annealed films ore oriented edge-on to the basal plane of the HOPG, which indicates that the influence of the octodecyl chains is not sufficient to tie the grids into a face-on orientation. To gain a detailed understanding of the self-assembly behaviour of the grid on HOPG, the results for the grid itself have been compared to those of its constituent ligands. |
Briggs, Breeze N; McMillin, David R; Durola, Fabien ; Sauvage, Jean-Pierre Photophysical properties of copper pseudorotaxanes Journal Article In: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 237 , 2009, ISSN: 0065-7727. @article{briggs_photophysical_2009, title = {Photophysical properties of copper pseudorotaxanes}, author = {Briggs, Breeze N. and McMillin, David R. and Durola, Fabien and Sauvage, Jean-Pierre}, issn = {0065-7727}, year = {2009}, date = {2009-03-01}, journal = {ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY}, volume = {237}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Collin, Jean-Paul ; Sauvage, Jean-Pierre Electroactive catenanes and rotaxanes: molecular machines prototypes Journal Article In: ACTUALITE CHIMIQUE, (327-28), pp. 114–119, 2009, ISSN: 0151-9093. @article{collin_electroactive_2009, title = {Electroactive catenanes and rotaxanes: molecular machines prototypes}, author = {Collin, Jean-Paul and Sauvage, Jean-Pierre}, issn = {0151-9093}, year = {2009}, date = {2009-03-01}, journal = {ACTUALITE CHIMIQUE}, number = {327-28}, pages = {114--119}, abstract = {In recent years, many dynamic molecular systems have been elaborated. They constitute the key elements of the emerging field of “molecular machine”. In these systems, large amplitude motions can be triggered by various external signals. Among them catenanes and rotaxanes play an important role since the inherent mechanical bonds restrict the degree of freedom of their components but permit motions like pirouetting, rotation or translation. Several examples of electrochemically triggered molecular machine prototypes based on catenanes and rotaxanes are described in this article. Recent spectacular results obtained with such systems are also discussed in the context of possible applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In recent years, many dynamic molecular systems have been elaborated. They constitute the key elements of the emerging field of “molecular machine”. In these systems, large amplitude motions can be triggered by various external signals. Among them catenanes and rotaxanes play an important role since the inherent mechanical bonds restrict the degree of freedom of their components but permit motions like pirouetting, rotation or translation. Several examples of electrochemically triggered molecular machine prototypes based on catenanes and rotaxanes are described in this article. Recent spectacular results obtained with such systems are also discussed in the context of possible applications. |
Nam, Kwangho ; Verdine, Gregory L; Karplus, Martin Molecular Mechanism of the Acceleration of the Damaged Base Extrusion and its Recognition by Bacterial MutM DNA Glycosylase: Free Energy Simulation Studies Journal Article In: BIOPHYSICAL JOURNAL, 96 (3, 1), pp. 342A, 2009, ISSN: 0006-3495. @article{nam_molecular_2009, title = {Molecular Mechanism of the Acceleration of the Damaged Base Extrusion and its Recognition by Bacterial MutM DNA Glycosylase: Free Energy Simulation Studies}, author = {Nam, Kwangho and Verdine, Gregory L. and Karplus, Martin}, issn = {0006-3495}, year = {2009}, date = {2009-02-01}, journal = {BIOPHYSICAL JOURNAL}, volume = {96}, number = {3, 1}, pages = {342A}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Biolo, Andreia ; Greferath, Ruth ; Siwik, Deborah A; Qin, Fuzhong ; Valsky, Eugene ; Fylaktakidou, Konstantina C; Pothukanuri, Srinivasu ; Duarte, Carolina D; Schwarz, Richard P; Lehn, Jean-Marie ; Nicolau, Claude ; Colucci, Wilson S Enhanced exercise capacity in mice with severe heart failure treated with an allosteric effector of hemoglobin, myo-inositol trispyrophosphate Journal Article In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 106 (6), pp. 1926–1929, 2009, ISSN: 0027-8424. @article{biolo_enhanced_2009, title = {Enhanced exercise capacity in mice with severe heart failure treated with an allosteric effector of hemoglobin, myo-inositol trispyrophosphate}, author = {Biolo, Andreia and Greferath, Ruth and Siwik, Deborah A. and Qin, Fuzhong and Valsky, Eugene and Fylaktakidou, Konstantina C. and Pothukanuri, Srinivasu and Duarte, Carolina D. and Schwarz, Richard P. and Lehn, Jean-Marie and Nicolau, Claude and Colucci, Wilson S.}, doi = {10.1073/pnas.0812381106}, issn = {0027-8424}, year = {2009}, date = {2009-02-01}, journal = {PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, volume = {106}, number = {6}, pages = {1926--1929}, abstract = {A major determinant of maximal exercise capacity is the delivery of oxygen to exercising muscles. myo-Inositol trispyrophosphate (ITPP) is a recently identified membrane-permeant molecule that causes allosteric regulation of Hb oxygen binding affinity. In normal mice, i.p. administration of ITPP (0.5-3 g/kg) caused a dose-related increase in the oxygen tension at which Hb is 50% saturated (p50), with a maximal increase of 31%. In parallel experiments, ITPP caused a dose-related increase in maximal exercise capacity, with a maximal increase of 57 +/- 13% (P = 0.002). In transgenic mice with severe heart failure caused by cardiac-specific overexpression of G alpha q, i.p. ITPP increased exercise capacity, with a maximal increase of 63 +/- 7% (P = 0.005). Oral administration of ITPP in drinking water increased Hb p50 and maximal exercise capacity (+34 +/- 10%; P textbackslashtextbackslashtextless 0.002) in normal and failing mice. Consistent with increased tissue oxygen availability, ITPP decreased hypoxia inducible factor-1 alpha mRNA expression in myocardium. It had no effect on myocardial contractility in isolated mouse cardiac myocytes and did not affect arterial blood pressure in vivo in mice. Thus, ITPP decreases the oxygen binding affinity of Hb, increases tissue oxygen delivery, and increases maximal exercise capacity in normal mice and mice with severe heart failure. ITPP is thus an attractive candidate for the therapy of patients with reduced exercise capacity caused by heart failure.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A major determinant of maximal exercise capacity is the delivery of oxygen to exercising muscles. myo-Inositol trispyrophosphate (ITPP) is a recently identified membrane-permeant molecule that causes allosteric regulation of Hb oxygen binding affinity. In normal mice, i.p. administration of ITPP (0.5-3 g/kg) caused a dose-related increase in the oxygen tension at which Hb is 50% saturated (p50), with a maximal increase of 31%. In parallel experiments, ITPP caused a dose-related increase in maximal exercise capacity, with a maximal increase of 57 +/- 13% (P = 0.002). In transgenic mice with severe heart failure caused by cardiac-specific overexpression of G alpha q, i.p. ITPP increased exercise capacity, with a maximal increase of 63 +/- 7% (P = 0.005). Oral administration of ITPP in drinking water increased Hb p50 and maximal exercise capacity (+34 +/- 10%; P textbackslashtextbackslashtextless 0.002) in normal and failing mice. Consistent with increased tissue oxygen availability, ITPP decreased hypoxia inducible factor-1 alpha mRNA expression in myocardium. It had no effect on myocardial contractility in isolated mouse cardiac myocytes and did not affect arterial blood pressure in vivo in mice. Thus, ITPP decreases the oxygen binding affinity of Hb, increases tissue oxygen delivery, and increases maximal exercise capacity in normal mice and mice with severe heart failure. ITPP is thus an attractive candidate for the therapy of patients with reduced exercise capacity caused by heart failure. |
Wenger, Jerome ; Gerard, Davy ; Aouani, Heykel ; Rigneault, Herve ; Lowder, Bryan ; Blair, Steve ; Devaux, Eloise ; Ebbesen, Thomas W Nanoaperture-Enhanced Signal-to-Noise Ratio in Fluorescence Correlation Spectroscopy Journal Article In: ANALYTICAL CHEMISTRY, 81 (2), pp. 834–839, 2009, ISSN: 0003-2700. @article{wenger_nanoaperture-enhanced_2009, title = {Nanoaperture-Enhanced Signal-to-Noise Ratio in Fluorescence Correlation Spectroscopy}, author = {Wenger, Jerome and Gerard, Davy and Aouani, Heykel and Rigneault, Herve and Lowder, Bryan and Blair, Steve and Devaux, Eloise and Ebbesen, Thomas W.}, doi = {10.1021/ac8024015}, issn = {0003-2700}, year = {2009}, date = {2009-01-01}, journal = {ANALYTICAL CHEMISTRY}, volume = {81}, number = {2}, pages = {834--839}, abstract = {The fluorescence enhancement found in gold nanoapertures is demonstrated to increase the signal-to-noise ratio (SNR) in fluorescence correlation spectroscopy (FCS). Starting from a general discussion on noise in FCS experiments, we show that fluorescence enhancement leads to a dramatic increase in the SNR. This prediction is confirmed by experiments where we report an experimental gain in SNR of about 1 order of magnitude, corresponding to a 100-fold reduction of the experiment duration. This technique is then applied to monitor the kinetics of a fast enzymatic cleavage reaction. This set of experiments evidence the feasibility of FCS analysis with fast integration times of about 1 s, opening the way to the monitoring of a variety of biochemical reactions at reduced time scales.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The fluorescence enhancement found in gold nanoapertures is demonstrated to increase the signal-to-noise ratio (SNR) in fluorescence correlation spectroscopy (FCS). Starting from a general discussion on noise in FCS experiments, we show that fluorescence enhancement leads to a dramatic increase in the SNR. This prediction is confirmed by experiments where we report an experimental gain in SNR of about 1 order of magnitude, corresponding to a 100-fold reduction of the experiment duration. This technique is then applied to monitor the kinetics of a fast enzymatic cleavage reaction. This set of experiments evidence the feasibility of FCS analysis with fast integration times of about 1 s, opening the way to the monitoring of a variety of biochemical reactions at reduced time scales. |
Salomon, Adi ; Genet, Cyriaque ; Ebbesen, Thomas W Molecule-Light Complex: Dynamics of Hybrid Molecule-Surface Plasmon States Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (46), pp. 8748–8751, 2009, ISSN: 1433-7851. @article{salomon_molecule-light_2009, title = {Molecule-Light Complex: Dynamics of Hybrid Molecule-Surface Plasmon States}, author = {Salomon, Adi and Genet, Cyriaque and Ebbesen, Thomas W.}, doi = {10.1002/anie.200903191}, issn = {1433-7851}, year = {2009}, date = {2009-01-01}, journal = {ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, volume = {48}, number = {46}, pages = {8748--8751}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Wenger, Jerome ; Gerard, Davy ; Lenne, Pierre-Francois ; Rigneault, Herve ; Bonod, Nicolas ; Popov, Evgeny ; Marguet, Didier ; Nelep, Constantin ; Ebbesen, Thomas W Biophotonics applications of nanometric apertures Journal Article In: INTERNATIONAL JOURNAL OF MATERIALS & PRODUCT TECHNOLOGY, 34 (4), pp. 488–506, 2009, ISSN: 0268-1900. @article{wenger_biophotonics_2009, title = {Biophotonics applications of nanometric apertures}, author = {Wenger, Jerome and Gerard, Davy and Lenne, Pierre-Francois and Rigneault, Herve and Bonod, Nicolas and Popov, Evgeny and Marguet, Didier and Nelep, Constantin and Ebbesen, Thomas W.}, doi = {10.1504/IJMPT.2009.025002}, issn = {0268-1900}, year = {2009}, date = {2009-01-01}, journal = {INTERNATIONAL JOURNAL OF MATERIALS & PRODUCT TECHNOLOGY}, volume = {34}, number = {4}, pages = {488--506}, abstract = {Nanometric apertures in a metallic film are easy to produce, robust and highly reproducible nanophotonic devices that possess a number of desirable properties for biophotonics. In this review, we will describe the exciting applications of sub-wavelength apertures towards the sensitive and specific characterisation of molecules.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nanometric apertures in a metallic film are easy to produce, robust and highly reproducible nanophotonic devices that possess a number of desirable properties for biophotonics. In this review, we will describe the exciting applications of sub-wavelength apertures towards the sensitive and specific characterisation of molecules. |
Kong, Yifei ; Karplus, Martin Signaling pathways of PDZ2 domain: A molecular dynamics interaction correlation analysis Journal Article In: PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS, 74 (1), pp. 145–154, 2009, ISSN: 0887-3585. @article{kong_signaling_2009, title = {Signaling pathways of PDZ2 domain: A molecular dynamics interaction correlation analysis}, author = {Kong, Yifei and Karplus, Martin}, doi = {10.1002/prot.22139}, issn = {0887-3585}, year = {2009}, date = {2009-01-01}, journal = {PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS}, volume = {74}, number = {1}, pages = {145--154}, abstract = {PDZ domains are found in many signaling proteins. One of their functions is to provide scaffolds for forming membrane-associated protein complexes by binding to the carboxyl termini of their partners. PDZ domains are thought also to play a signal transduction role by propagating the information that binding has occurred to remote sites. In this study, a molecular dynamics (MD) simulation-based approach, referred to as an interaction correlation analysis, is applied to the PDZ2 domain to identify the possible signal transduction pathways. A residue correlation matrix is constructed from the interaction energy correlations between all residue pairs obtained from the MD simulations. Two continuous interaction pathways, starting at the ligand binding pocket, are identified by a hierarchical clustering analysis of the residue correlation matrix. One pathway is mainly localized at the N-terminal side of helix alpha l and the adjacent C-terminus of loop beta 1-beta 2. The other pathway is perpendicular to the central beta-sheet and extends toward the side of PDZ2 domain opposite to the ligand binding pocket. The results complement previous studies based on multiple sequence analysis, NMR, and MD simulations. Importantly, they reveal the energetic origin of the long-range coupling. The PDZ2 results, as well as the earlier rhodopsin analysis, show that the interaction correlation analysis is a robust approach for determining pathways of intramolecular signal transduction.}, keywords = {}, pubstate = {published}, tppubtype = {article} } PDZ domains are found in many signaling proteins. One of their functions is to provide scaffolds for forming membrane-associated protein complexes by binding to the carboxyl termini of their partners. PDZ domains are thought also to play a signal transduction role by propagating the information that binding has occurred to remote sites. In this study, a molecular dynamics (MD) simulation-based approach, referred to as an interaction correlation analysis, is applied to the PDZ2 domain to identify the possible signal transduction pathways. A residue correlation matrix is constructed from the interaction energy correlations between all residue pairs obtained from the MD simulations. Two continuous interaction pathways, starting at the ligand binding pocket, are identified by a hierarchical clustering analysis of the residue correlation matrix. One pathway is mainly localized at the N-terminal side of helix alpha l and the adjacent C-terminus of loop beta 1-beta 2. The other pathway is perpendicular to the central beta-sheet and extends toward the side of PDZ2 domain opposite to the ligand binding pocket. The results complement previous studies based on multiple sequence analysis, NMR, and MD simulations. Importantly, they reveal the energetic origin of the long-range coupling. The PDZ2 results, as well as the earlier rhodopsin analysis, show that the interaction correlation analysis is a robust approach for determining pathways of intramolecular signal transduction. |
Llanes-Pallas, Anna ; Palma, Carlos-Andres ; Piot, Luc ; Belbakra, Abdelhalim ; Listorti, Andrea ; Prato, Maurizio ; Samori, Paolo ; Armaroli, Nicola ; Bonifazi, Davide Engineering of Supramolecular Ħ-Bonded Nanopolygons via Self-Assembly of Programmed Molecular Modules Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (2), pp. 509–520, 2009, ISSN: 0002-7863. @article{llanes-pallas_engineering_2009, title = {Engineering of Supramolecular Ħ-Bonded Nanopolygons via Self-Assembly of Programmed Molecular Modules}, author = {Llanes-Pallas, Anna and Palma, Carlos-Andres and Piot, Luc and Belbakra, Abdelhalim and Listorti, Andrea and Prato, Maurizio and Samori, Paolo and Armaroli, Nicola and Bonifazi, Davide}, doi = {10.1021/ja807530m}, issn = {0002-7863}, year = {2009}, date = {2009-01-01}, journal = {JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, volume = {131}, number = {2}, pages = {509--520}, abstract = {Discrete and multicomponent nanoscale noncovalent assemblies on surfaces featuring polygonal porous domains are presented. The molecular engineering concept involves multivalent molecular modules that are preprogrammed to undergo heteromolecular recognition by exploiting complementary multiple H bonds. Two types of molecular modules have been engineered: (i) a linear unit of twofold symmetry exposing two 2,6-di(acylamino)pyridyl[donor-acceptor-donor (DAD)] recognition sites at its extremities with a 180 degrees orientation relative to each other and (ii) an angular unit constituted by a 1,3,6,8-tetraethynylpyrene core peripherally functionalized with four uracil groups [acceptor-donor-acceptor (ADA)] positioned at 60 degrees and 120 degrees relative to each other. These molecular modules self-assemble through H-bonds between the complementary recognition sites, forming supramolecular architectures. Their symmetry depends upon the type of each individual subunit and the stoichiometry as well as on the combination and distribution of the main symmetry axes. These so-formed two-dimensional (2D) supramolecular oligomers have been studied in solution by optical spectroscopy and on highly ordered pyrolitic graphite (HOPG) substrates by scanning tunneling microscopy (STM) at the solid-liquid interface. Steady-state UV/vis absorption and emission titration measurements suggest the reversible formation of multiple oligomeric species with slightly modulated fluorescence spectra. This likely reflects the presence of various aggregates between the two polytopic receptors, which exhibit somewhat different electronic delocalization as a function of the aggregate size. The presence of multiple species is further confirmed by time-resolved luminescence measurements: lifetime values are fitted as double/multiple exponentials and are always shorter than 6.5 ns. The formation of several oligomeric species is further supported by in situ STM measurements at the solid-liquid interface that provided evidence, with submolecular resolution, for the formation of multicomponent and discrete 2D polygon-like assemblies. We highlight the role of accurate control of the concentration required to image on the surface the 2D oligomeric species formed in solution, which allows us to bypass the determinant role of the substrate-molecule interactions in forming the thermodynamically stable monocomponent architectures at the solid-liquid interface.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Discrete and multicomponent nanoscale noncovalent assemblies on surfaces featuring polygonal porous domains are presented. The molecular engineering concept involves multivalent molecular modules that are preprogrammed to undergo heteromolecular recognition by exploiting complementary multiple H bonds. Two types of molecular modules have been engineered: (i) a linear unit of twofold symmetry exposing two 2,6-di(acylamino)pyridyl[donor-acceptor-donor (DAD)] recognition sites at its extremities with a 180 degrees orientation relative to each other and (ii) an angular unit constituted by a 1,3,6,8-tetraethynylpyrene core peripherally functionalized with four uracil groups [acceptor-donor-acceptor (ADA)] positioned at 60 degrees and 120 degrees relative to each other. These molecular modules self-assemble through H-bonds between the complementary recognition sites, forming supramolecular architectures. Their symmetry depends upon the type of each individual subunit and the stoichiometry as well as on the combination and distribution of the main symmetry axes. These so-formed two-dimensional (2D) supramolecular oligomers have been studied in solution by optical spectroscopy and on highly ordered pyrolitic graphite (HOPG) substrates by scanning tunneling microscopy (STM) at the solid-liquid interface. Steady-state UV/vis absorption and emission titration measurements suggest the reversible formation of multiple oligomeric species with slightly modulated fluorescence spectra. This likely reflects the presence of various aggregates between the two polytopic receptors, which exhibit somewhat different electronic delocalization as a function of the aggregate size. The presence of multiple species is further confirmed by time-resolved luminescence measurements: lifetime values are fitted as double/multiple exponentials and are always shorter than 6.5 ns. The formation of several oligomeric species is further supported by in situ STM measurements at the solid-liquid interface that provided evidence, with submolecular resolution, for the formation of multicomponent and discrete 2D polygon-like assemblies. We highlight the role of accurate control of the concentration required to image on the surface the 2D oligomeric species formed in solution, which allows us to bypass the determinant role of the substrate-molecule interactions in forming the thermodynamically stable monocomponent architectures at the solid-liquid interface. |
Ciesielski, Artur ; Schaeffer, Gael ; Petitjean, Anne ; Lehn, Jean-Marie ; Samori, Paolo STM Insight into Hydrogen-Bonded Bicomponent 1D Supramolecular Polymers with Controlled Geometries at the Liquid-Solid Interface Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (11), pp. 2039–2043, 2009, ISSN: 1433-7851. @article{ciesielski_stm_2009, title = {STM Insight into Hydrogen-Bonded Bicomponent 1D Supramolecular Polymers with Controlled Geometries at the Liquid-Solid Interface}, author = {Ciesielski, Artur and Schaeffer, Gael and Petitjean, Anne and Lehn, Jean-Marie and Samori, Paolo}, doi = {10.1002/anie.200805680}, issn = {1433-7851}, year = {2009}, date = {2009-01-01}, journal = {ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, volume = {48}, number = {11}, pages = {2039--2043}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Schwartz, Erik ; Palermo, Vincenzo ; Finlayson, Chris E; Huang, Ya-Shih ; Otten, Matthijs B L; Liscio, Andrea ; Trapani, Sara ; Gonzalez-Valls, Irene ; Brocorens, Patrick ; Cornelissen, Jeroen J L M; Peneva, Kalina ; Muellen, Klaus ; Spano, Frank C; Yartsev, Arkady ; Westenhoff, Sebastian ; Friend, Richard H; Beljonne, David ; Nolte, Roeland J M; Samori, Paolo ; Rowan, Alan E “Helter-Skelter-Like” Perylene Polyisocyanopeptides Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (11), pp. 2536–2547, 2009, ISSN: 0947-6539. @article{schwartz_helter-skelter-like_2009, title = {“Helter-Skelter-Like” Perylene Polyisocyanopeptides}, author = {Schwartz, Erik and Palermo, Vincenzo and Finlayson, Chris E. and Huang, Ya-Shih and Otten, Matthijs B. L. and Liscio, Andrea and Trapani, Sara and Gonzalez-Valls, Irene and Brocorens, Patrick and Cornelissen, Jeroen J. L. M. and Peneva, Kalina and Muellen, Klaus and Spano, Frank C. and Yartsev, Arkady and Westenhoff, Sebastian and Friend, Richard H. and Beljonne, David and Nolte, Roeland J. M. and Samori, Paolo and Rowan, Alan E.}, doi = {10.1002/chem.200801746}, issn = {0947-6539}, year = {2009}, date = {2009-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {15}, number = {11}, pages = {2536--2547}, abstract = {We report on a combined experimental and computational investigation on the synthesis and thorough characterization of the structure of perylene-functionalized polyisocyanides. Spectroscopic analyses and extensive molecular dynamics studies revealed a well defined 4, helix in which the perylene molecules form four “helter skelter-like” overlapping pathways along which excitons and electrons can rapidly migrate. The well-defined polymer scaffold stabilized by hydrogen bonding, to which the chromophores are attached, accounts for the precise architectural definition, and molecular stiffness observed for these molecules. Molecular-dynamics studies showed that the chirality present in these polymers is expressed in the formation of stable right-handed helices. The formation of chiral supramolecular structures is further supported by the measured and calculated bisignated Cotton effect. The structural definition of the chromophores aligned in one direction along the backbone is highlighted by the extremely efficient exciton migration rates and charge densities measured with Transient Absorption Spectroscopy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report on a combined experimental and computational investigation on the synthesis and thorough characterization of the structure of perylene-functionalized polyisocyanides. Spectroscopic analyses and extensive molecular dynamics studies revealed a well defined 4, helix in which the perylene molecules form four “helter skelter-like” overlapping pathways along which excitons and electrons can rapidly migrate. The well-defined polymer scaffold stabilized by hydrogen bonding, to which the chromophores are attached, accounts for the precise architectural definition, and molecular stiffness observed for these molecules. Molecular-dynamics studies showed that the chirality present in these polymers is expressed in the formation of stable right-handed helices. The formation of chiral supramolecular structures is further supported by the measured and calculated bisignated Cotton effect. The structural definition of the chromophores aligned in one direction along the backbone is highlighted by the extremely efficient exciton migration rates and charge densities measured with Transient Absorption Spectroscopy. |
Piot, Luc ; Meudtner, Robert M; El Malah, Tamer ; Hecht, Stefan ; Samori, Paolo Modulating Large-Area Self-Assembly at the Solid-Liquid Interface by pH-Mediated Conformational Switching Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (19), pp. 4788–4792, 2009, ISSN: 0947-6539. @article{piot_modulating_2009, title = {Modulating Large-Area Self-Assembly at the Solid-Liquid Interface by pH-Mediated Conformational Switching}, author = {Piot, Luc and Meudtner, Robert M. and El Malah, Tamer and Hecht, Stefan and Samori, Paolo}, doi = {10.1002/chem.200802566}, issn = {0947-6539}, year = {2009}, date = {2009-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {15}, number = {19}, pages = {4788--4792}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Zeitouny, Joceline ; Aurisicchio, Claudia ; Bonifazi, Davide ; De Zorzi, Rita ; Geremia, Silvano ; Bonini, Massimo ; Palma, Carlos-Andres ; Samori, Paolo ; Listorti, Andrea ; Belbakra, Abdelhalim ; Armaroli, Nicola Photoinduced structural modifications in multicomponent architectures containing azobenzene moieties as photoswitchable cores Journal Article In: JOURNAL OF MATERIALS CHEMISTRY, 19 (27), pp. 4715–4724, 2009, ISSN: 0959-9428. @article{zeitouny_photoinduced_2009, title = {Photoinduced structural modifications in multicomponent architectures containing azobenzene moieties as photoswitchable cores}, author = {Zeitouny, Joceline and Aurisicchio, Claudia and Bonifazi, Davide and De Zorzi, Rita and Geremia, Silvano and Bonini, Massimo and Palma, Carlos-Andres and Samori, Paolo and Listorti, Andrea and Belbakra, Abdelhalim and Armaroli, Nicola}, doi = {10.1039/b905287a}, issn = {0959-9428}, year = {2009}, date = {2009-01-01}, journal = {JOURNAL OF MATERIALS CHEMISTRY}, volume = {19}, number = {27}, pages = {4715--4724}, abstract = {Four novel pi-conjugated chromophores with an azobenzene core (1-4) have been synthesized exploiting Pd-catalysed cross-coupling reactions between ethynyl-bearing azobenzene cores and suitably-designed peripheral groups. While in molecules 2 and 3 the azobenzene core is equipped, respectively, with ethynyl and 1,3-butadiyne spacers terminated with a substituted aniline, molecule 4 is an homologue of derivative 2 in which the terminal moieties are replaced by meso-substituted Zn-porphyrins. X-Ray crystallographic studies of substituted azobenzene 2 reveal a nearly planar arrangement of the four phenyl rings and the trans configuration of the N=N central unit. The UV-Vis absorption spectrum of molecule 1 in cyclohexane (CHX) is very similar to that of unsubstituted azobenzenes; upon irradiation at the maximum of the intense pi-pi absorption feature (360 nm), 1 undergoes trans -textbackslashtextbackslashtextgreater cis photoisomerization reaching a photostationary state. The process is fully reversible both photochemically and thermally (ca. 120 min in the dark). The UV-Vis electronic absorption features of 2-4 are dramatically different compared to those of 1, but the photochemical process can still be traced and exhibits full reversibility in CHX. Also in the case of compound 4, where the photoreactive azobenzene excited states might be quenched by the low-lying porphyrin electronic levels, the photoreaction does occur. Extensive STM investigations of self-assembled monolayers (SAMs) of 2 and 3 at the solid/liquid interface were performed by means of scanning tunneling microscopy (STM) on highly oriented pyrolytic graphite (HOPG). It is evidenced that only the trans isomer can be physisorbed on the surface whereas the cis form, either produced under illumination in situ or prepared by irradiation of the solution prior to deposition (ex-situ), is never observed on the surface. The smallest azobenzene 1 and the bisporphyrin system 4 did not physisorb onto the surface because of the very small size and the bulky 3,5-di(tert-butyl)phenyl groups hindering flat adsorption on HOPG, respectively.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Four novel pi-conjugated chromophores with an azobenzene core (1-4) have been synthesized exploiting Pd-catalysed cross-coupling reactions between ethynyl-bearing azobenzene cores and suitably-designed peripheral groups. While in molecules 2 and 3 the azobenzene core is equipped, respectively, with ethynyl and 1,3-butadiyne spacers terminated with a substituted aniline, molecule 4 is an homologue of derivative 2 in which the terminal moieties are replaced by meso-substituted Zn-porphyrins. X-Ray crystallographic studies of substituted azobenzene 2 reveal a nearly planar arrangement of the four phenyl rings and the trans configuration of the N=N central unit. The UV-Vis absorption spectrum of molecule 1 in cyclohexane (CHX) is very similar to that of unsubstituted azobenzenes; upon irradiation at the maximum of the intense pi-pi absorption feature (360 nm), 1 undergoes trans -textbackslashtextbackslashtextgreater cis photoisomerization reaching a photostationary state. The process is fully reversible both photochemically and thermally (ca. 120 min in the dark). The UV-Vis electronic absorption features of 2-4 are dramatically different compared to those of 1, but the photochemical process can still be traced and exhibits full reversibility in CHX. Also in the case of compound 4, where the photoreactive azobenzene excited states might be quenched by the low-lying porphyrin electronic levels, the photoreaction does occur. Extensive STM investigations of self-assembled monolayers (SAMs) of 2 and 3 at the solid/liquid interface were performed by means of scanning tunneling microscopy (STM) on highly oriented pyrolytic graphite (HOPG). It is evidenced that only the trans isomer can be physisorbed on the surface whereas the cis form, either produced under illumination in situ or prepared by irradiation of the solution prior to deposition (ex-situ), is never observed on the surface. The smallest azobenzene 1 and the bisporphyrin system 4 did not physisorb onto the surface because of the very small size and the bulky 3,5-di(tert-butyl)phenyl groups hindering flat adsorption on HOPG, respectively. |
Treossi, Emanuele ; Liscio, Andrea ; Feng, Xinliang ; Palermo, Vincenzo ; Muellen, Klaus ; Samori, Paolo Temperature-Enhanced Solvent Vapor Annealing of a C-3 Symmetric Hexa-peri-Hexabenzocoronene: Controlling the Self-Assembly from Nano- to Macroscale Journal Article In: SMALL, 5 (1), pp. 112–119, 2009, ISSN: 1613-6810. @article{treossi_temperature-enhanced_2009, title = {Temperature-Enhanced Solvent Vapor Annealing of a C-3 Symmetric Hexa-peri-Hexabenzocoronene: Controlling the Self-Assembly from Nano- to Macroscale}, author = {Treossi, Emanuele and Liscio, Andrea and Feng, Xinliang and Palermo, Vincenzo and Muellen, Klaus and Samori, Paolo}, doi = {10.1002/smll.200801002}, issn = {1613-6810}, year = {2009}, date = {2009-01-01}, journal = {SMALL}, volume = {5}, number = {1}, pages = {112--119}, abstract = {Temperature-enhanced solvent vapor annealing (TESVA) is used to self assemble functionalized polycyclic aromatic hydrocarbon molecules into ordered macroscopic layers and crystals on solid surfaces. A novel C-3 symmetric hexa-peri-hexabenzocoronene functionalized with alternating hydrophilic and hydrophobic side chains is used as a model system since its multivalent character can be expected to offer unique self-assembly properties and behavior in different solvents. TESVA promotes the molecule's long-range mobility, as proven by their diffusion on a Si/SiOx surface on a scale of hundreds of micrometers. This leads to self-assembly into large, ordered crystals featuring an edge-on columnar type of arrangement, which differs from the morphologies obtained using conventional solution-processing methods such as spin-coating or drop-casting. The temperature modulation in the TESVA makes it possible to achieve an additional control over the role of hydrodynamic forces in the self-assembly at surfaces, leading to a macroscopic self-healing within the adsorbed film notably improved as compared to conventional solvent vapor annealing. This surface re-organization can be monitored in real time by optical and atomic force microscopy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Temperature-enhanced solvent vapor annealing (TESVA) is used to self assemble functionalized polycyclic aromatic hydrocarbon molecules into ordered macroscopic layers and crystals on solid surfaces. A novel C-3 symmetric hexa-peri-hexabenzocoronene functionalized with alternating hydrophilic and hydrophobic side chains is used as a model system since its multivalent character can be expected to offer unique self-assembly properties and behavior in different solvents. TESVA promotes the molecule's long-range mobility, as proven by their diffusion on a Si/SiOx surface on a scale of hundreds of micrometers. This leads to self-assembly into large, ordered crystals featuring an edge-on columnar type of arrangement, which differs from the morphologies obtained using conventional solution-processing methods such as spin-coating or drop-casting. The temperature modulation in the TESVA makes it possible to achieve an additional control over the role of hydrodynamic forces in the self-assembly at surfaces, leading to a macroscopic self-healing within the adsorbed film notably improved as compared to conventional solvent vapor annealing. This surface re-organization can be monitored in real time by optical and atomic force microscopy. |
Palermo, Vincenzo ; Schwartz, Erik ; Liscio, Andrea ; Otten, Matthijs B J; Muellen, Klaus ; Nolte, Roeland J M; Rowan, Alan E; Samori, Paolo Influence of pi-pi stacking on the self-assembly and coiling of multi-chromophoric polymers based on perylenebis(dicarboximides): an AFM study Journal Article In: SOFT MATTER, 5 (23), pp. 4680–4686, 2009, ISSN: 1744-683X. @article{palermo_influence_2009, title = {Influence of pi-pi stacking on the self-assembly and coiling of multi-chromophoric polymers based on perylenebis(dicarboximides): an AFM study}, author = {Palermo, Vincenzo and Schwartz, Erik and Liscio, Andrea and Otten, Matthijs B. J. and Muellen, Klaus and Nolte, Roeland J. M. and Rowan, Alan E. and Samori, Paolo}, doi = {10.1039/b912302d}, issn = {1744-683X}, year = {2009}, date = {2009-01-01}, journal = {SOFT MATTER}, volume = {5}, number = {23}, pages = {4680--4686}, abstract = {The assembly behavior at surfaces of very stiff polyisocyanopeptides (PICs) functionalized with semiconducting perylenebis(dicarboximide) (PDI) side chains has been investigated by atomic force microscopy. These multi-chromophoric arrays are unique as they combine an ultra-stiff central polymer main-chain scaffold upon which the PDI chromophores can self-organize through pi-pi stacking, making them interesting and versatile building blocks for nanoelectronics. In this paper we compare three PIC derivatives featuring different side groups: M1-no chromophores, M2-chromophores capable of pi-pi stacking, and M3-chromophores where the stacking is hindered by the presence of bulky substituents in the bay area of the PDI. The effect of the different side functionalizations on the macromolecule assembly at surfaces was compared by studying the morphology and aggregation tendency of all three polymers when adsorbed on silicon, mica and graphite substrates. Making use of nano-manipulation of these functional rods with the AFM tip gave insight into the polymer structure and its coiling behaviour.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The assembly behavior at surfaces of very stiff polyisocyanopeptides (PICs) functionalized with semiconducting perylenebis(dicarboximide) (PDI) side chains has been investigated by atomic force microscopy. These multi-chromophoric arrays are unique as they combine an ultra-stiff central polymer main-chain scaffold upon which the PDI chromophores can self-organize through pi-pi stacking, making them interesting and versatile building blocks for nanoelectronics. In this paper we compare three PIC derivatives featuring different side groups: M1-no chromophores, M2-chromophores capable of pi-pi stacking, and M3-chromophores where the stacking is hindered by the presence of bulky substituents in the bay area of the PDI. The effect of the different side functionalizations on the macromolecule assembly at surfaces was compared by studying the morphology and aggregation tendency of all three polymers when adsorbed on silicon, mica and graphite substrates. Making use of nano-manipulation of these functional rods with the AFM tip gave insight into the polymer structure and its coiling behaviour. |
Lehn, Jean-Marie ; Fersht, Alan R Interfaces: Two Worlds Unite Journal Article In: CHEMBIOCHEM, 10 (1), pp. 4, 2009, ISSN: 1439-4227. @article{lehn_interfaces:_2009, title = {Interfaces: Two Worlds Unite}, author = {Lehn, Jean-Marie and Fersht, Alan R.}, doi = {10.1002/cbic.200800740}, issn = {1439-4227}, year = {2009}, date = {2009-01-01}, journal = {CHEMBIOCHEM}, volume = {10}, number = {1}, pages = {4}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Fujii, Shunsuke ; Lehn, Jean-Marie Structural and Functional Evolution of a Library of Constitutional Dynamic Polymers Driven by Alkali Metal Ion Recognition Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (41), pp. 7635–7638, 2009, ISSN: 1433-7851. @article{fujii_structural_2009, title = {Structural and Functional Evolution of a Library of Constitutional Dynamic Polymers Driven by Alkali Metal Ion Recognition}, author = {Fujii, Shunsuke and Lehn, Jean-Marie}, doi = {10.1002/anie.200902512}, issn = {1433-7851}, year = {2009}, date = {2009-01-01}, journal = {ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, volume = {48}, number = {41}, pages = {7635--7638}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Folmer-Andersen, Frantz J; Lehn, Jean-Marie Constitutional Adaptation of Dynamic Polymers: Hydrophobically Driven Sequence Selection in Dynamic Covalent Polyacylhydrazones Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (41), pp. 7664–7667, 2009, ISSN: 1433-7851. @article{folmer-andersen_constitutional_2009, title = {Constitutional Adaptation of Dynamic Polymers: Hydrophobically Driven Sequence Selection in Dynamic Covalent Polyacylhydrazones}, author = {Folmer-Andersen, J. Frantz and Lehn, Jean-Marie}, doi = {10.1002/anie.200902487}, issn = {1433-7851}, year = {2009}, date = {2009-01-01}, journal = {ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, volume = {48}, number = {41}, pages = {7664--7667}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Herrmann, Andreas ; Giuseppone, Nicolas ; Lehn, Jean-Marie Electric-Field Triggered Controlled Release of Bioactive Volatiles from Imine-Based Liquid Crystalline Phases Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (1), pp. 117–124, 2009, ISSN: 0947-6539. @article{herrmann_electric-field_2009, title = {Electric-Field Triggered Controlled Release of Bioactive Volatiles from Imine-Based Liquid Crystalline Phases}, author = {Herrmann, Andreas and Giuseppone, Nicolas and Lehn, Jean-Marie}, doi = {10.1002/chem.200801782}, issn = {0947-6539}, year = {2009}, date = {2009-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {15}, number = {1}, pages = {117--124}, abstract = {Application of an electric field to liquid crystalline film forming imines with negative dielectric anisotropy, such as N-(4-methoxybenzylidene)-4-butylaniline (MBBA, 1), results in the expulsion of compounds that do not participate in the formation of the liquid crystalline phase. Furthermore, amines and aromatic aldehydes undergo component exchange with the imine by generating constitutional dynamic libraries. The strength of the electric field and the duration of its application to the liquid crystalline film influence the release rate of the expelled compounds and, at the same time, modulate the equilibration of the dynamic libraries. The controlled release of volatile organic molecules with different chemical functionalities from the film was quantified by dynamic headspace analysis. In all cases, higher headspace concentrations were detected in the presence of an electric field. These results point to the possibility of using imine-based liquid crystalline films to build devices for the controlled release of a broad variety of bioactive volatiles as a direct response to an external electric signal.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Application of an electric field to liquid crystalline film forming imines with negative dielectric anisotropy, such as N-(4-methoxybenzylidene)-4-butylaniline (MBBA, 1), results in the expulsion of compounds that do not participate in the formation of the liquid crystalline phase. Furthermore, amines and aromatic aldehydes undergo component exchange with the imine by generating constitutional dynamic libraries. The strength of the electric field and the duration of its application to the liquid crystalline film influence the release rate of the expelled compounds and, at the same time, modulate the equilibration of the dynamic libraries. The controlled release of volatile organic molecules with different chemical functionalities from the film was quantified by dynamic headspace analysis. In all cases, higher headspace concentrations were detected in the presence of an electric field. These results point to the possibility of using imine-based liquid crystalline films to build devices for the controlled release of a broad variety of bioactive volatiles as a direct response to an external electric signal. |
Reutenauer, P; Buhler, E; Boul, P J; Candau, S J; Lehn, J-M Room Temperature Dynamic Polymers Based on Diels-Alder Chemistry Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (8), pp. 1893–1900, 2009, ISSN: 0947-6539. @article{reutenauer_room_2009, title = {Room Temperature Dynamic Polymers Based on Diels-Alder Chemistry}, author = {Reutenauer, P. and Buhler, E. and Boul, P. J. and Candau, S. J. and Lehn, J-M.}, doi = {10.1002/chem.200802145}, issn = {0947-6539}, year = {2009}, date = {2009-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {15}, number = {8}, pages = {1893--1900}, abstract = {Dynamers based oil reversible Diels-Alder chemistry have been obtained and shown to undergo dynamic exchange at room temperature. Their study in solution by small-angle neutron scattering indicated the formation of long and highly flexible chains. Polydispersed molecules gave T(g) values below room temperature, permitting the generation of a dynamic elastomer upon introduction of a dynamic cross-linking agent. The use of a system with a low equilibrium constant gives access to materials with interesting self-healing properties.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Dynamers based oil reversible Diels-Alder chemistry have been obtained and shown to undergo dynamic exchange at room temperature. Their study in solution by small-angle neutron scattering indicated the formation of long and highly flexible chains. Polydispersed molecules gave T(g) values below room temperature, permitting the generation of a dynamic elastomer upon introduction of a dynamic cross-linking agent. The use of a system with a low equilibrium constant gives access to materials with interesting self-healing properties. |
Ulrich, Sebastien ; Buhler, Eric ; Lehn, Jean-Marie Reversible constitutional switching between macrocycles and polymers induced by shape change in a dynamic covalent system Journal Article In: NEW JOURNAL OF CHEMISTRY, 33 (2), pp. 271–292, 2009, ISSN: 1144-0546. @article{ulrich_reversible_2009, title = {Reversible constitutional switching between macrocycles and polymers induced by shape change in a dynamic covalent system}, author = {Ulrich, Sebastien and Buhler, Eric and Lehn, Jean-Marie}, doi = {10.1039/b817261g}, issn = {1144-0546}, year = {2009}, date = {2009-01-01}, journal = {NEW JOURNAL OF CHEMISTRY}, volume = {33}, number = {2}, pages = {271--292}, abstract = {We report here the development of morphological switches as a new tool that can be used in constitutional dynamic chemistry (CDC) to control the constitution of the whole dynamic system. Molecules that have well-defined but switchable shapes were designed and synthesized. Their restrained conformational states were characterized both in the solid and in solution. The addition of metal ions induces a shape change through coordination; the shape generated was also fully investigated both in the solid and in solution. Such molecules constitute morphological switches, meaning that they can explore various shape states as a result of controlled well-defined shape changes triggered by an effector. These morphological switches were then integrated into covalent dynamic systems through formation of reversible imine bonds. Thermodynamic and kinetic analyses were performed in order to quantify the covalent equilibrium and to investigate the labile character of the covalent reversible link. It was then demonstrated that the molecular shape state of the morphological switches induces a well-defined constitution through covalent self-assembly, and that the system can be steered, quantitatively and reversibly without significant fatigue, between two different constitutional states, respectively, polymeric and macrocyclic assemblies. The dynamic covalent polymeric assemblies were analysed by DOSY NMR and small angle neutrons scattering (SANS). Their dynamic behaviour as a function of the concentration and the temperature was demonstrated and characterized.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report here the development of morphological switches as a new tool that can be used in constitutional dynamic chemistry (CDC) to control the constitution of the whole dynamic system. Molecules that have well-defined but switchable shapes were designed and synthesized. Their restrained conformational states were characterized both in the solid and in solution. The addition of metal ions induces a shape change through coordination; the shape generated was also fully investigated both in the solid and in solution. Such molecules constitute morphological switches, meaning that they can explore various shape states as a result of controlled well-defined shape changes triggered by an effector. These morphological switches were then integrated into covalent dynamic systems through formation of reversible imine bonds. Thermodynamic and kinetic analyses were performed in order to quantify the covalent equilibrium and to investigate the labile character of the covalent reversible link. It was then demonstrated that the molecular shape state of the morphological switches induces a well-defined constitution through covalent self-assembly, and that the system can be steered, quantitatively and reversibly without significant fatigue, between two different constitutional states, respectively, polymeric and macrocyclic assemblies. The dynamic covalent polymeric assemblies were analysed by DOSY NMR and small angle neutrons scattering (SANS). Their dynamic behaviour as a function of the concentration and the temperature was demonstrated and characterized. |
Rosso-Vasic, Milena ; Spruijt, Evan ; Popovic, Zoran ; Overgaag, Karin ; van Lagen, Barend ; Grandidier, Bruno ; Vanmaekelbergh, Daniel ; Dominguez-Gutierrez, David ; De Cola, Luisa ; Zuilhof, Han Amine-terminated silicon nanoparticles: synthesis, optical properties and their use in bioimaging Journal Article In: JOURNAL OF MATERIALS CHEMISTRY, 19 (33), pp. 5926–5933, 2009, ISSN: 0959-9428. @article{rosso-vasic_amine-terminated_2009, title = {Amine-terminated silicon nanoparticles: synthesis, optical properties and their use in bioimaging}, author = {Rosso-Vasic, Milena and Spruijt, Evan and Popovic, Zoran and Overgaag, Karin and van Lagen, Barend and Grandidier, Bruno and Vanmaekelbergh, Daniel and Dominguez-Gutierrez, David and De Cola, Luisa and Zuilhof, Han}, doi = {10.1039/b902671a}, issn = {0959-9428}, year = {2009}, date = {2009-01-01}, journal = {JOURNAL OF MATERIALS CHEMISTRY}, volume = {19}, number = {33}, pages = {5926--5933}, abstract = {Very stable and bright emitting amine-terminated Si nanoparticles (NPs) with different alkyl chain lengths between the Si core and amine end-group are synthesized. The obtained NPs have a spherical shape and homogeneous size distribution (1.57 +/- 0.24 nm). Their emission can be tuned from the UV to the blue spectral region, in a controllable fashion, by only changing the alkyl spacer length. The emission quantum yields are similar to 12% for all synthesized Si NPs. Excited state lifetimes are in the ns range and point to a direct band gap excitation. NH(2)-terminated Si NPs exhibit an exceptional stability over a wide pH range (1-13) and high temperatures (120 degrees C). The diffusion coefficient of prepared Si NPs is determined by fluorescence correlation spectroscopy (FCS) to be 3.3 x 10(-10) m(2) s(-1). The derived size of Si NPs from mobility corresponds to 1.4 nm which is in a good agreement with the size obtained by transmission electron microscopy ( TEM). Prepared Si NPs are shown to be highly suitable for bioimaging studies as they are readily taken up by BV2 cells. Si NPs are located in the cells cytosol. Proliferation of stained BV2 cells is observed and showed that newly formed cells are also stained with Si NPs, indicating their minimal toxicity. By using Si NPs it is possible to stain multiple cell generations by only staining the mother cells.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Very stable and bright emitting amine-terminated Si nanoparticles (NPs) with different alkyl chain lengths between the Si core and amine end-group are synthesized. The obtained NPs have a spherical shape and homogeneous size distribution (1.57 +/- 0.24 nm). Their emission can be tuned from the UV to the blue spectral region, in a controllable fashion, by only changing the alkyl spacer length. The emission quantum yields are similar to 12% for all synthesized Si NPs. Excited state lifetimes are in the ns range and point to a direct band gap excitation. NH(2)-terminated Si NPs exhibit an exceptional stability over a wide pH range (1-13) and high temperatures (120 degrees C). The diffusion coefficient of prepared Si NPs is determined by fluorescence correlation spectroscopy (FCS) to be 3.3 x 10(-10) m(2) s(-1). The derived size of Si NPs from mobility corresponds to 1.4 nm which is in a good agreement with the size obtained by transmission electron microscopy ( TEM). Prepared Si NPs are shown to be highly suitable for bioimaging studies as they are readily taken up by BV2 cells. Si NPs are located in the cells cytosol. Proliferation of stained BV2 cells is observed and showed that newly formed cells are also stained with Si NPs, indicating their minimal toxicity. By using Si NPs it is possible to stain multiple cell generations by only staining the mother cells. |
Gorska, Katarzyna ; Huang, Kuo-Ting ; Chaloin, Olivier ; Winssinger, Nicolas DNA-Templated Homo- and Heterodimerization of Peptide Nucleic Acid Encoded Oligosaccharides that Mimick the Carbohydrate Epitope of HIV Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (41), pp. 7695–7700, 2009, ISSN: 1433-7851. @article{gorska_dna-templated_2009, title = {DNA-Templated Homo- and Heterodimerization of Peptide Nucleic Acid Encoded Oligosaccharides that Mimick the Carbohydrate Epitope of HIV}, author = {Gorska, Katarzyna and Huang, Kuo-Ting and Chaloin, Olivier and Winssinger, Nicolas}, doi = {10.1002/anie.200903328}, issn = {1433-7851}, year = {2009}, date = {2009-01-01}, journal = {ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, volume = {48}, number = {41}, pages = {7695--7700}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Dakas, Pierre-Yves ; Jogireddy, Rajamalleswaramma ; Valot, Gaelle ; Barluenga, Sofia ; Winssinger, Nicolas Divergent Syntheses of Resorcylic Acid Lactones: L-783277, LL-Z1640-2, and Hypothemycin Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (43), pp. 11490–11497, 2009, ISSN: 0947-6539. @article{dakas_divergent_2009, title = {Divergent Syntheses of Resorcylic Acid Lactones: L-783277, LL-Z1640-2, and Hypothemycin}, author = {Dakas, Pierre-Yves and Jogireddy, Rajamalleswaramma and Valot, Gaelle and Barluenga, Sofia and Winssinger, Nicolas}, doi = {10.1002/chem.200901373}, issn = {0947-6539}, year = {2009}, date = {2009-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {15}, number = {43}, pages = {11490--11497}, abstract = {The resorcylic acid factories (RAL) are endowed with diverse biological activity ranging from transcription factor modulators (zearalenone and zearalenol) to HSP90 inhibitors (radicicol and pochonin D) and reversible (aigialomycin D) as well as irreversible kinase inhibitors (hypothemycin and other RAL containing a cis-enone). Our interest in broadening the diversity of this family beyond naturally occurring diversity has led us to seek a general approach that could be used to address the entire spectrum of functionalities present within this family. Herein, we present our efforts on accessing macrocycles bearing an alkane., alkene, or epoxide at the benzylic position from a common benzylic sulfide intermediate to access L-783277, LL-Z1640-2, and hypothemycin.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The resorcylic acid factories (RAL) are endowed with diverse biological activity ranging from transcription factor modulators (zearalenone and zearalenol) to HSP90 inhibitors (radicicol and pochonin D) and reversible (aigialomycin D) as well as irreversible kinase inhibitors (hypothemycin and other RAL containing a cis-enone). Our interest in broadening the diversity of this family beyond naturally occurring diversity has led us to seek a general approach that could be used to address the entire spectrum of functionalities present within this family. Herein, we present our efforts on accessing macrocycles bearing an alkane., alkene, or epoxide at the benzylic position from a common benzylic sulfide intermediate to access L-783277, LL-Z1640-2, and hypothemycin. |
Jogireddy, Rajamalleswaramma ; Dakas, Pierre-Yves ; Valot, Gaelle ; Barluenga, Sofia ; Winssinger, Nicolas Synthesis of a Resorcylic Acid Lactone (RAL) Library Using Fluorous-Mixture Synthesis and Profile of its Selectivity Against a Panel of Kinases Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (43), pp. 11498–11506, 2009, ISSN: 0947-6539. @article{jogireddy_synthesis_2009, title = {Synthesis of a Resorcylic Acid Lactone (RAL) Library Using Fluorous-Mixture Synthesis and Profile of its Selectivity Against a Panel of Kinases}, author = {Jogireddy, Rajamalleswaramma and Dakas, Pierre-Yves and Valot, Gaelle and Barluenga, Sofia and Winssinger, Nicolas}, doi = {10.1002/chem.200901375}, issn = {0947-6539}, year = {2009}, date = {2009-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {15}, number = {43}, pages = {11498--11506}, abstract = {A library of resorcylic acid lactones (RAL) containing a cis-enone moiety targeting kinases hearing a cysteine residue within the ATP-binding pocket was prepared using a fluorous-mixture synthesis and evaluated against a panel of 19 kinases thus providing important structure-activity trends. Two new analogues were then profiled for their selectivity against a panel of 402 kinases providing the broadest evaluation of this pharmacophores' selectivity}, keywords = {}, pubstate = {published}, tppubtype = {article} } A library of resorcylic acid lactones (RAL) containing a cis-enone moiety targeting kinases hearing a cysteine residue within the ATP-binding pocket was prepared using a fluorous-mixture synthesis and evaluated against a panel of 19 kinases thus providing important structure-activity trends. Two new analogues were then profiled for their selectivity against a panel of 402 kinases providing the broadest evaluation of this pharmacophores' selectivity |
Collin, Jean-Paul ; Durola, Fabien ; Lux, Jacques ; Sauvage, Jean-Pierre A Rapidly Shuttling Copper-Complexed [2]Rotaxane with Three Different Chelating Groups in Its Axis Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (45), pp. 8532–8535, 2009, ISSN: 1433-7851. @article{collin_rapidly_2009, title = {A Rapidly Shuttling Copper-Complexed [2]Rotaxane with Three Different Chelating Groups in Its Axis}, author = {Collin, Jean-Paul and Durola, Fabien and Lux, Jacques and Sauvage, Jean-Pierre}, doi = {10.1002/anie.200903311}, issn = {1433-7851}, year = {2009}, date = {2009-01-01}, journal = {ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, volume = {48}, number = {45}, pages = {8532--8535}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Collin, Jean-Paul ; Mobian, Pierre ; Sauvage, Jean-Pierre ; Sour, Angelique ; Yan, Yi-Ming ; Willner, Itamar Copper-Complexed Pirouetting [2]pseudorotaxanes with Sulfur-Containing End-Groups Attached to the Thread: Synthesis, Electrochemical Studies, and Deposition on Gold Electrodes Journal Article In: AUSTRALIAN JOURNAL OF CHEMISTRY, 62 (10), pp. 1231–1237, 2009, ISSN: 0004-9425. @article{collin_copper-complexed_2009, title = {Copper-Complexed Pirouetting [2]pseudorotaxanes with Sulfur-Containing End-Groups Attached to the Thread: Synthesis, Electrochemical Studies, and Deposition on Gold Electrodes}, author = {Collin, Jean-Paul and Mobian, Pierre and Sauvage, Jean-Pierre and Sour, Angelique and Yan, Yi-Ming and Willner, Itamar}, doi = {10.1071/CH09334}, issn = {0004-9425}, year = {2009}, date = {2009-01-01}, journal = {AUSTRALIAN JOURNAL OF CHEMISTRY}, volume = {62}, number = {10}, pages = {1231--1237}, abstract = {Two copper [2]pseudorotaxanes incorporating a macrocycle with two chelating sites (2,9-diphenyl-1,10-phenanthroline and 2,2',6',2 `'-terpyridine) and a thread based on crescent-shaped 2,2'-bipyridine derivatives have been synthesized and characterized. One of the threads was a hindering 2,2'-bipyridine functionalized by two thioctic-ended arms. The second thread was an 8,8'-diphenyl-3,3'-biisoquinoline functionalized by two thioether-ended arms. The electrochemical studies of the two copper [2] pseudorotaxanes, both in solution and anchored on a gold surface, showed only fast-moving systems in solution. The reasons of the inertness of the deposited complexes on gold electrode have been explored.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two copper [2]pseudorotaxanes incorporating a macrocycle with two chelating sites (2,9-diphenyl-1,10-phenanthroline and 2,2',6',2 `'-terpyridine) and a thread based on crescent-shaped 2,2'-bipyridine derivatives have been synthesized and characterized. One of the threads was a hindering 2,2'-bipyridine functionalized by two thioctic-ended arms. The second thread was an 8,8'-diphenyl-3,3'-biisoquinoline functionalized by two thioether-ended arms. The electrochemical studies of the two copper [2] pseudorotaxanes, both in solution and anchored on a gold surface, showed only fast-moving systems in solution. The reasons of the inertness of the deposited complexes on gold electrode have been explored. |
Collin, Jean-Paul ; Durola, Fabien ; Frey, Julien ; Heitz, Valerie ; Sauvage, Jean-Pierre ; Tock, Christian ; Trolez, Yann Quantitative formation of [4]pseudorotaxanes from two rods and two bis-macrocycles incorporating porphyrinic plates between the rings Journal Article In: CHEMICAL COMMUNICATIONS, (13), pp. 1706–1708, 2009, ISSN: 1359-7345. @article{collin_quantitative_2009, title = {Quantitative formation of [4]pseudorotaxanes from two rods and two bis-macrocycles incorporating porphyrinic plates between the rings}, author = {Collin, Jean-Paul and Durola, Fabien and Frey, Julien and Heitz, Valerie and Sauvage, Jean-Pierre and Tock, Christian and Trolez, Yann}, doi = {10.1039/b901482a}, issn = {1359-7345}, year = {2009}, date = {2009-01-01}, journal = {CHEMICAL COMMUNICATIONS}, number = {13}, pages = {1706--1708}, abstract = {[4]Pseudorotaxanes consisting of two very large coordinating bis-macrocycles and rigid rods incorporating two side-by-side chelates have been obtained quantitatively utilising the gathering and threading effect of copper(I); the assemblies obtained are several nanometres long and they contain two face-to-face zinc porphyrins which will be used to complex various organic substrates.}, keywords = {}, pubstate = {published}, tppubtype = {article} } [4]Pseudorotaxanes consisting of two very large coordinating bis-macrocycles and rigid rods incorporating two side-by-side chelates have been obtained quantitatively utilising the gathering and threading effect of copper(I); the assemblies obtained are several nanometres long and they contain two face-to-face zinc porphyrins which will be used to complex various organic substrates. |
Faiz, Jonathan A; Heitz, Valerie ; Sauvage, Jean-Pierre Design and synthesis of porphyrin-containing catenanes and rotaxanes Journal Article In: CHEMICAL SOCIETY REVIEWS, 38 (2), pp. 422–442, 2009, ISSN: 0306-0012. @article{faiz_design_2009, title = {Design and synthesis of porphyrin-containing catenanes and rotaxanes}, author = {Faiz, Jonathan A. and Heitz, Valerie and Sauvage, Jean-Pierre}, doi = {10.1039/b710908n}, issn = {0306-0012}, year = {2009}, date = {2009-01-01}, journal = {CHEMICAL SOCIETY REVIEWS}, volume = {38}, number = {2}, pages = {422--442}, abstract = {Catenanes and rotaxanes containing porphyrin subunits have become popular synthetic targets because of the large variety of available synthetic strategies including the coordination chemistry of metallated porphyrins, coupled with the many attractive physical properties of porphyrins. This tutorial review outlines various synthetic approaches and templating strategies that have been used to prepare a range of mechanically interlocked architectures that incorporate porphyrins as fundamental subunits either grafted onto macrocycles or as stoppers. These species are of interest in relation to recreating natural processes such as the photosynthetic apparatus or enzyme binding sites.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Catenanes and rotaxanes containing porphyrin subunits have become popular synthetic targets because of the large variety of available synthetic strategies including the coordination chemistry of metallated porphyrins, coupled with the many attractive physical properties of porphyrins. This tutorial review outlines various synthetic approaches and templating strategies that have been used to prepare a range of mechanically interlocked architectures that incorporate porphyrins as fundamental subunits either grafted onto macrocycles or as stoppers. These species are of interest in relation to recreating natural processes such as the photosynthetic apparatus or enzyme binding sites. |
Periyasamy, Ganga ; Collin, Jean-Paul ; Sauvage, Jean-Pierre ; Levine, Raphael D; Remacle, Francoise Electrochemically Driven Sequential Machines: An Implementation of Copper Rotaxanes Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (6), pp. 1310–1313, 2009, ISSN: 0947-6539. @article{periyasamy_electrochemically_2009, title = {Electrochemically Driven Sequential Machines: An Implementation of Copper Rotaxanes}, author = {Periyasamy, Ganga and Collin, Jean-Paul and Sauvage, Jean-Pierre and Levine, Raphael D. and Remacle, Francoise}, doi = {10.1002/chem.200802249}, issn = {0947-6539}, year = {2009}, date = {2009-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {15}, number = {6}, pages = {1310--1313}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Durola, Fabien ; Lux, Jacques ; Sauvage, Jean-Pierre A Fast-Moving Copper-Based Molecular Shuttle: Synthesis and Dynamic Properties Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (16), pp. 4124–4134, 2009, ISSN: 0947-6539. @article{durola_fast-moving_2009, title = {A Fast-Moving Copper-Based Molecular Shuttle: Synthesis and Dynamic Properties}, author = {Durola, Fabien and Lux, Jacques and Sauvage, Jean-Pierre}, doi = {10.1002/chem.200802510}, issn = {0947-6539}, year = {2009}, date = {2009-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {15}, number = {16}, pages = {4124--4134}, abstract = {The present report deals with the synthesis of a two-station [2]rotaxane consisting of a dpbiiq-incorporating macrocyele (dpbiiq: ,8,8'-diphenyl-3,3'-biisoquinoline) threaded by a coordinating fragment whose complexing units are a dpp and a terpy ligand (dpp: 2,9-diphenyl-1,10-phenanthroline: terpy: 2,2'6',2 `'-terpyridine). The [2]rotaxane was prepared in 11 steps from commercially available or easy-to-make molecules, without taking into account the preparation of the dpbiiq-containing 39-membered ring, which was available in our group. The ring-incorporated bidentate chelate is at the same time endocyclic and sterically nonhindering, which is a specific property of the dpbiiq-coordinating unit. This unique feature has a profound influence on the rate of the ring-and-copper translation notion between the stations of the axle. Based on an analogous multistep strategy a related molecular shuttle has also been prepared that contains exactly the same axle and Stoppers as the First compound but whose threaded ring incorporates the sterically hindering dpp chelate. The translation motions of this other system are several orders of magnitude slower than the corresponding movements of the dpbiiq-based compound. The motion corresponding to the rearrangement of the unstable five-coordinate cooper(I) form of the compounds is relatively fast for both shuttles; the half lifetime of the five-coordinate Cu-I species being below 20 ms for the dpbiiq-containing system and below 1 s for the dpp-based molecule. The reverse motion corresponding to the rearrangement of the four-coordinate copper (II) complexes is much slower, especially for the dpp-based system. It is of the order of several hours for the dpp-based shuttle and only one second or less for the dpbiiq system, under exactly the same conditions. The remarkable difference between the motion rates for the two two-station shuttles demonstrates that the use of a very open chelate such as dpbiiq is extremely beneficial in the context of fast-moving molecular machines.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present report deals with the synthesis of a two-station [2]rotaxane consisting of a dpbiiq-incorporating macrocyele (dpbiiq: ,8,8'-diphenyl-3,3'-biisoquinoline) threaded by a coordinating fragment whose complexing units are a dpp and a terpy ligand (dpp: 2,9-diphenyl-1,10-phenanthroline: terpy: 2,2'6',2 `'-terpyridine). The [2]rotaxane was prepared in 11 steps from commercially available or easy-to-make molecules, without taking into account the preparation of the dpbiiq-containing 39-membered ring, which was available in our group. The ring-incorporated bidentate chelate is at the same time endocyclic and sterically nonhindering, which is a specific property of the dpbiiq-coordinating unit. This unique feature has a profound influence on the rate of the ring-and-copper translation notion between the stations of the axle. Based on an analogous multistep strategy a related molecular shuttle has also been prepared that contains exactly the same axle and Stoppers as the First compound but whose threaded ring incorporates the sterically hindering dpp chelate. The translation motions of this other system are several orders of magnitude slower than the corresponding movements of the dpbiiq-based compound. The motion corresponding to the rearrangement of the unstable five-coordinate cooper(I) form of the compounds is relatively fast for both shuttles; the half lifetime of the five-coordinate Cu-I species being below 20 ms for the dpbiiq-containing system and below 1 s for the dpp-based molecule. The reverse motion corresponding to the rearrangement of the four-coordinate copper (II) complexes is much slower, especially for the dpp-based system. It is of the order of several hours for the dpp-based shuttle and only one second or less for the dpbiiq system, under exactly the same conditions. The remarkable difference between the motion rates for the two two-station shuttles demonstrates that the use of a very open chelate such as dpbiiq is extremely beneficial in the context of fast-moving molecular machines. |
Baranoff, Etienne D; Voignier, Julie ; Yasuda, Takuma ; Heitz, Valerie ; Sauvage, Jean-Pierre ; Kato, Takashi Macrocycle-Based Liquid Crystals: A Study of Topological Effects on Mesomorphism Journal Article In: MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 509 , pp. 907–914, 2009, ISSN: 1542-1406. @article{baranoff_macrocycle-based_2009, title = {Macrocycle-Based Liquid Crystals: A Study of Topological Effects on Mesomorphism}, author = {Baranoff, Etienne D. and Voignier, Julie and Yasuda, Takuma and Heitz, Valerie and Sauvage, Jean-Pierre and Kato, Takashi}, doi = {10.1080/15421400903065606}, issn = {1542-1406}, year = {2009}, date = {2009-01-01}, journal = {MOLECULAR CRYSTALS AND LIQUID CRYSTALS}, volume = {509}, pages = {907--914}, abstract = {A liquid-crystalline molecule based on a macrocycle and a forklike mesogen forms smectic A phases over a wide temperature range. This thermal behavior of the macrocycle-based compound has been compared with that of the corresponding catenane molecule.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A liquid-crystalline molecule based on a macrocycle and a forklike mesogen forms smectic A phases over a wide temperature range. This thermal behavior of the macrocycle-based compound has been compared with that of the corresponding catenane molecule. |
Collin, Jean-Paul ; Sauvage, Jean-Pierre ; Trolez, Yann ; Rissanen, Kari [3]Rotaxanes and [3]pseudorotaxanes with a rigid two-bidentate chelate axle threaded through two coordinating rings Journal Article In: NEW JOURNAL OF CHEMISTRY, 33 (10), pp. 2148–2154, 2009, ISSN: 1144-0546. @article{collin_[3]rotaxanes_2009, title = {[3]Rotaxanes and [3]pseudorotaxanes with a rigid two-bidentate chelate axle threaded through two coordinating rings}, author = {Collin, Jean-Paul and Sauvage, Jean-Pierre and Trolez, Yann and Rissanen, Kari}, doi = {10.1039/b9nj00278b}, issn = {1144-0546}, year = {2009}, date = {2009-01-01}, journal = {NEW JOURNAL OF CHEMISTRY}, volume = {33}, number = {10}, pages = {2148--2154}, abstract = {New [3]rotaxanes and [3]pseudorotaxanes have been synthesised using the “gathering and threading” effect of copper(I). By using click chemistry as the “stoppering” reaction, a good yield of the [3]rotaxane was obtained, either as a dicopper complex or as a metal-free compound after demetallation. The axle contains a central rigid aromatic block incorporating two bidentate chelates, and the threaded macrocycles are 30-membered rings. A model dicopper(I) [3]pseudorotaxane whose axle was end-functionalised by triisopropylsilyl groups could be crystallised and studied by X-ray diffraction. A particularly attractive structure was obtained showing a “slanted” geometry for the two rings and the axle, the two 1,10-phenanthroline units of the rings being almost parallel to one another but their respective mean planes being more than 7 angstrom apart.}, keywords = {}, pubstate = {published}, tppubtype = {article} } New [3]rotaxanes and [3]pseudorotaxanes have been synthesised using the “gathering and threading” effect of copper(I). By using click chemistry as the “stoppering” reaction, a good yield of the [3]rotaxane was obtained, either as a dicopper complex or as a metal-free compound after demetallation. The axle contains a central rigid aromatic block incorporating two bidentate chelates, and the threaded macrocycles are 30-membered rings. A model dicopper(I) [3]pseudorotaxane whose axle was end-functionalised by triisopropylsilyl groups could be crystallised and studied by X-ray diffraction. A particularly attractive structure was obtained showing a “slanted” geometry for the two rings and the axle, the two 1,10-phenanthroline units of the rings being almost parallel to one another but their respective mean planes being more than 7 angstrom apart. |
2008 |
Khalil, Ahmad S; Appleyard, David C; Labno, Anna K; Georges, Adrien ; Karplus, Martin ; Belcher, Angela M; Hwang, Wonmuk ; Lang, Matthew J Kinesin's cover-neck bundle folds forward to generate force Journal Article In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 105 (49), pp. 19247–19252, 2008, ISSN: 0027-8424. @article{khalil_kinesins_2008, title = {Kinesin's cover-neck bundle folds forward to generate force}, author = {Khalil, Ahmad S. and Appleyard, David C. and Labno, Anna K. and Georges, Adrien and Karplus, Martin and Belcher, Angela M. and Hwang, Wonmuk and Lang, Matthew J.}, doi = {10.1073/pnas.0805147105}, issn = {0027-8424}, year = {2008}, date = {2008-12-01}, journal = {PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, volume = {105}, number = {49}, pages = {19247--19252}, abstract = {Each step of the kinesin motor involves a force-generating molecular rearrangement. Although significant progress has been made in elucidating the broad features of the kinesin mechanochemical cycle, molecular details of the force generation mechanism remain a mystery. Recent molecular dynamics simulations have suggested a mechanism in which the forward drive is produced when the N-terminal cover strand forms a beta-sheet with the neck linker to yield the cover-neck bundle. We tested this proposal by comparing optical trapping motility measurements of cover strand mutants with the wild-type. Motility data, as well as kinetic analyses, revealed impairment of the force-generating capacity accompanied by a greater load dependence in the mechanochemical cycle. In particular, a mutant with the cover strand deleted functioned only marginally, despite the fact that the cover strand, the N-terminal “dangling end,” unlike the neck linker and nucleotide-binding pocket, is not involved with any previously considered energy transduction pathway. Furthermore, a constant assisting load, likely in lieu of a power stroke, was shown to rescue forward motility in the cover strand deletion mutant. Our results support a stepping mechanism driven by dynamic cover-neck bundle formation. They also suggest a strategy to generate motors with altered mechanical characteristics by targeting the force-generating element.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Each step of the kinesin motor involves a force-generating molecular rearrangement. Although significant progress has been made in elucidating the broad features of the kinesin mechanochemical cycle, molecular details of the force generation mechanism remain a mystery. Recent molecular dynamics simulations have suggested a mechanism in which the forward drive is produced when the N-terminal cover strand forms a beta-sheet with the neck linker to yield the cover-neck bundle. We tested this proposal by comparing optical trapping motility measurements of cover strand mutants with the wild-type. Motility data, as well as kinetic analyses, revealed impairment of the force-generating capacity accompanied by a greater load dependence in the mechanochemical cycle. In particular, a mutant with the cover strand deleted functioned only marginally, despite the fact that the cover strand, the N-terminal “dangling end,” unlike the neck linker and nucleotide-binding pocket, is not involved with any previously considered energy transduction pathway. Furthermore, a constant assisting load, likely in lieu of a power stroke, was shown to rescue forward motility in the cover strand deletion mutant. Our results support a stepping mechanism driven by dynamic cover-neck bundle formation. They also suggest a strategy to generate motors with altered mechanical characteristics by targeting the force-generating element. |
Banerjee, Anirban ; Fromme, Christopher J; Jiralerspong, Sao ; Radom, Christopher T; Bruner, Steven D; Chung, Sang Jeon ; Yang, Wei ; Karplus, Martin ; Verdine, Gregory L Interrogation, Recognition, and Repair of Damaged Bases in DNA Journal Article In: CHEMICAL RESEARCH IN TOXICOLOGY, 21 (12), pp. 2433, 2008, ISSN: 0893-228X. @article{banerjee_interrogation_2008, title = {Interrogation, Recognition, and Repair of Damaged Bases in DNA}, author = {Banerjee, Anirban and Fromme, J. Christopher and Jiralerspong, Sao and Radom, Christopher T. and Bruner, Steven D. and Chung, Sang Jeon and Yang, Wei and Karplus, Martin and Verdine, Gregory L.}, issn = {0893-228X}, year = {2008}, date = {2008-12-01}, journal = {CHEMICAL RESEARCH IN TOXICOLOGY}, volume = {21}, number = {12}, pages = {2433}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Finlayson, Chris E; Friend, Richard H; Otten, Matthijs B J; Schwartz, Erik ; Cornelissen, Jeroen. J L M; Nolte, Roeland. L M; Rowan, Alan E; Samori, Paolo ; Palermo, Vicenzo ; Liscio, Andrea ; Peneva, Kalina ; Muellen, Klaus ; Trapani, Sara ; Beljonne, David Electronic Transport Properties or Ensembles of Perylene-Substituted Poly-isocyanopeptide Arrays Journal Article In: ADVANCED FUNCTIONAL MATERIALS, 18 (24), pp. 3947–3955, 2008, ISSN: 1616-301X. @article{finlayson_electronic_2008, title = {Electronic Transport Properties or Ensembles of Perylene-Substituted Poly-isocyanopeptide Arrays}, author = {Finlayson, Chris E. and Friend, Richard H. and Otten, Matthijs B. J. and Schwartz, Erik and Cornelissen, Jeroen. J. L. M. and Nolte, Roeland. L. M. and Rowan, Alan E. and Samori, Paolo and Palermo, Vicenzo and Liscio, Andrea and Peneva, Kalina and Muellen, Klaus and Trapani, Sara and Beljonne, David}, doi = {10.1002/adfm.200800943}, issn = {1616-301X}, year = {2008}, date = {2008-12-01}, journal = {ADVANCED FUNCTIONAL MATERIALS}, volume = {18}, number = {24}, pages = {3947--3955}, abstract = {The electronic transport properties of stacks of perylene-bis(dicarboximide) (PDI) chromophores, covalently fixed to the side arms of rigid, helical polyisocyanopeptides, are studied using thin-film transistors. In device architectures where the transistor channel lengths are somewhat greater than the average polymer chain length, carrier mobilities of order 10(-3) cm(2) V(-1) s(-1) at 350K are found, which are limited by inter-chain transport processes. The influence of pi-pi interactions on the material properties is studied by using PDIs with and without bulky substituents in the bay area. In order to attain a deeper understanding of both the electronic and the electronic-transport Properties of these systems, studies of self-assembly on surfaces are combined with electronic characterization using Kelvin probe force microscopy, and also a theoretical study of electronic coupling. The use of a rigid polymer backbone as a scaffold to achieve a full control Over the position and orientation of functional groups is of general applicability and interest in the design of building blocks for technologically important functional materials, as well as in more fundamental studies of chromophoric interactions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The electronic transport properties of stacks of perylene-bis(dicarboximide) (PDI) chromophores, covalently fixed to the side arms of rigid, helical polyisocyanopeptides, are studied using thin-film transistors. In device architectures where the transistor channel lengths are somewhat greater than the average polymer chain length, carrier mobilities of order 10(-3) cm(2) V(-1) s(-1) at 350K are found, which are limited by inter-chain transport processes. The influence of pi-pi interactions on the material properties is studied by using PDIs with and without bulky substituents in the bay area. In order to attain a deeper understanding of both the electronic and the electronic-transport Properties of these systems, studies of self-assembly on surfaces are combined with electronic characterization using Kelvin probe force microscopy, and also a theoretical study of electronic coupling. The use of a rigid polymer backbone as a scaffold to achieve a full control Over the position and orientation of functional groups is of general applicability and interest in the design of building blocks for technologically important functional materials, as well as in more fundamental studies of chromophoric interactions. |
Puntoriero, Fausto ; Campagna, Sebastiano ; Stadler, Adrian-Mihail ; Lehn, Jean-Marie Luminescence properties and redox behavior of Ru(II) molecular racks Journal Article In: COORDINATION CHEMISTRY REVIEWS, 252 (23-24, SI), pp. 2480–2492, 2008, ISSN: 0010-8545. @article{puntoriero_luminescence_2008, title = {Luminescence properties and redox behavior of Ru(II) molecular racks}, author = {Puntoriero, Fausto and Campagna, Sebastiano and Stadler, Adrian-Mihail and Lehn, Jean-Marie}, doi = {10.1016/j.ccr.2007.12.009}, issn = {0010-8545}, year = {2008}, date = {2008-12-01}, journal = {COORDINATION CHEMISTRY REVIEWS}, volume = {252}, number = {23-24, SI}, pages = {2480--2492}, abstract = {The absorption spectra, luminescence properties, and redox behavior of Ru(II) molecular racks are reviewed, together with the same properties of closely related systems, including homo- (Fe(II)) and hetero-metallic (Fe(II)[Ru(II) and Fe(II)/Os(II)) molecular gtids and their mononuclear Ru(II) and Os(II) precursors, and bis-dirhodiurn(II, II) molecular racks. The systems discussed are based on polytopic molecular strands made of poly(pyridine-pyrimidine), poly(naphthyridine-pyrimidine), and poly(hydrazone-pyrimidine/pyrazine) subunits. Linearly-arranged systems based on tris-terpyridine molecular strands are also reported for completeness. The results indicate that the title species are quite promising multicomponent systems for the development of functional supramolecular systems, with particular regards towards the design of nano-organized species featuring information storage functions, molecular wire-type behavior, and light-harvesting antennae properties. (C) 2007 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The absorption spectra, luminescence properties, and redox behavior of Ru(II) molecular racks are reviewed, together with the same properties of closely related systems, including homo- (Fe(II)) and hetero-metallic (Fe(II)[Ru(II) and Fe(II)/Os(II)) molecular gtids and their mononuclear Ru(II) and Os(II) precursors, and bis-dirhodiurn(II, II) molecular racks. The systems discussed are based on polytopic molecular strands made of poly(pyridine-pyrimidine), poly(naphthyridine-pyrimidine), and poly(hydrazone-pyrimidine/pyrazine) subunits. Linearly-arranged systems based on tris-terpyridine molecular strands are also reported for completeness. The results indicate that the title species are quite promising multicomponent systems for the development of functional supramolecular systems, with particular regards towards the design of nano-organized species featuring information storage functions, molecular wire-type behavior, and light-harvesting antennae properties. (C) 2007 Elsevier B.V. All rights reserved. |
Publications
2009 |
Computational, Structural, and Mechanistic Analysis of the Electrochemically Driven Pirouetting Motion of a Copper Rotaxane Journal Article In: JOURNAL OF PHYSICAL CHEMISTRY B, 113 (18), pp. 6219–6229, 2009, ISSN: 1520-6106. |
Enhanced optical transmission at the cutoff transition Journal Article In: OPTICS EXPRESS, 17 (9), pp. 6920–6930, 2009, ISSN: 1094-4087. |
Gaussian-Mixture Umbrella Sampling Journal Article In: JOURNAL OF PHYSICAL CHEMISTRY B, 113 (14), pp. 4664–4673, 2009, ISSN: 1520-6106. |
Selective Formation of Bi-Component Arrays Through Ħ-Bonding of Multivalent Molecular Modules Journal Article In: ADVANCED FUNCTIONAL MATERIALS, 19 (8), pp. 1207–1214, 2009, ISSN: 1616-301X. |
Supramolecular Crystal Engineering at the Solid-Liquid interface from First Principles: Toward Unraveling the Thermodynamics of 2D Self-Assembly Journal Article In: ADVANCED MATERIALS, 21 (13), pp. 1383–1386, 2009, ISSN: 0935-9648. |
Large-area bi-component processing of organic semiconductors by spray deposition and spin coating with orthogonal solvents Journal Article In: APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 95 (1, SI), pp. 15–20, 2009, ISSN: 0947-8396. |
Dynamic Diels-Alder Reactions of 9,10-Dimethylanthracene: Reversible Adduct Formation, Dynamic Exchange Processes and Thermal Fluorescence Modulation Journal Article In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, (11), pp. 1691–1697, 2009, ISSN: 1434-193X. |
Adjustable Receptor Based on a [3]Rotaxane Whose Two Threaded Rings Are Rigidly Attached to Two Porphyrinic Plates: Synthesis and Complexation Studies Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (15), pp. 5609–5620, 2009, ISSN: 0002-7863. |
Nanofocusing with Channel Plasmon Polaritons Journal Article In: NANO LETTERS, 9 (3), pp. 1278–1282, 2009, ISSN: 1530-6984. |
Taming Complexity: From Supramolecules to Suprafunctions Journal Article In: ADVANCED MATERIALS, 21 (10-11), pp. 1037–1040, 2009, ISSN: 0935-9648. |
Molecular Tectonics at the Solid/Liquid Interface: Controlling the Nanoscale Geometry, Directionality, and Packing of 1D Coordination Networks on Graphite Surfaces Journal Article In: ADVANCED MATERIALS, 21 (10-11), pp. 1131–1136, 2009, ISSN: 0935-9648. |
Copper(II) Dinuclear Pyrazine-Based Rack-Type Complexes: Preparation, Structure, and Magnetic Properties Journal Article In: INORGANIC CHEMISTRY, 48 (6), pp. 2456–2463, 2009, ISSN: 0020-1669. |
Self-Assembly of Alkoxy-Substituted Bis(hydrazone)-Based Organic Ligands and of a Metallosupramolecular Grid on Graphite Journal Article In: CHEMPHYSCHEM, 10 (4), pp. 699–705, 2009, ISSN: 1439-4235. |
Photophysical properties of copper pseudorotaxanes Journal Article In: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 237 , 2009, ISSN: 0065-7727. |
Electroactive catenanes and rotaxanes: molecular machines prototypes Journal Article In: ACTUALITE CHIMIQUE, (327-28), pp. 114–119, 2009, ISSN: 0151-9093. |
Molecular Mechanism of the Acceleration of the Damaged Base Extrusion and its Recognition by Bacterial MutM DNA Glycosylase: Free Energy Simulation Studies Journal Article In: BIOPHYSICAL JOURNAL, 96 (3, 1), pp. 342A, 2009, ISSN: 0006-3495. |
Enhanced exercise capacity in mice with severe heart failure treated with an allosteric effector of hemoglobin, myo-inositol trispyrophosphate Journal Article In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 106 (6), pp. 1926–1929, 2009, ISSN: 0027-8424. |
Nanoaperture-Enhanced Signal-to-Noise Ratio in Fluorescence Correlation Spectroscopy Journal Article In: ANALYTICAL CHEMISTRY, 81 (2), pp. 834–839, 2009, ISSN: 0003-2700. |
Molecule-Light Complex: Dynamics of Hybrid Molecule-Surface Plasmon States Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (46), pp. 8748–8751, 2009, ISSN: 1433-7851. |
Biophotonics applications of nanometric apertures Journal Article In: INTERNATIONAL JOURNAL OF MATERIALS & PRODUCT TECHNOLOGY, 34 (4), pp. 488–506, 2009, ISSN: 0268-1900. |
Signaling pathways of PDZ2 domain: A molecular dynamics interaction correlation analysis Journal Article In: PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS, 74 (1), pp. 145–154, 2009, ISSN: 0887-3585. |
Engineering of Supramolecular Ħ-Bonded Nanopolygons via Self-Assembly of Programmed Molecular Modules Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (2), pp. 509–520, 2009, ISSN: 0002-7863. |
STM Insight into Hydrogen-Bonded Bicomponent 1D Supramolecular Polymers with Controlled Geometries at the Liquid-Solid Interface Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (11), pp. 2039–2043, 2009, ISSN: 1433-7851. |
“Helter-Skelter-Like” Perylene Polyisocyanopeptides Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (11), pp. 2536–2547, 2009, ISSN: 0947-6539. |
Modulating Large-Area Self-Assembly at the Solid-Liquid Interface by pH-Mediated Conformational Switching Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (19), pp. 4788–4792, 2009, ISSN: 0947-6539. |
Photoinduced structural modifications in multicomponent architectures containing azobenzene moieties as photoswitchable cores Journal Article In: JOURNAL OF MATERIALS CHEMISTRY, 19 (27), pp. 4715–4724, 2009, ISSN: 0959-9428. |
Temperature-Enhanced Solvent Vapor Annealing of a C-3 Symmetric Hexa-peri-Hexabenzocoronene: Controlling the Self-Assembly from Nano- to Macroscale Journal Article In: SMALL, 5 (1), pp. 112–119, 2009, ISSN: 1613-6810. |
Influence of pi-pi stacking on the self-assembly and coiling of multi-chromophoric polymers based on perylenebis(dicarboximides): an AFM study Journal Article In: SOFT MATTER, 5 (23), pp. 4680–4686, 2009, ISSN: 1744-683X. |
Interfaces: Two Worlds Unite Journal Article In: CHEMBIOCHEM, 10 (1), pp. 4, 2009, ISSN: 1439-4227. |
Structural and Functional Evolution of a Library of Constitutional Dynamic Polymers Driven by Alkali Metal Ion Recognition Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (41), pp. 7635–7638, 2009, ISSN: 1433-7851. |
Constitutional Adaptation of Dynamic Polymers: Hydrophobically Driven Sequence Selection in Dynamic Covalent Polyacylhydrazones Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (41), pp. 7664–7667, 2009, ISSN: 1433-7851. |
Electric-Field Triggered Controlled Release of Bioactive Volatiles from Imine-Based Liquid Crystalline Phases Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (1), pp. 117–124, 2009, ISSN: 0947-6539. |
Room Temperature Dynamic Polymers Based on Diels-Alder Chemistry Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (8), pp. 1893–1900, 2009, ISSN: 0947-6539. |
Reversible constitutional switching between macrocycles and polymers induced by shape change in a dynamic covalent system Journal Article In: NEW JOURNAL OF CHEMISTRY, 33 (2), pp. 271–292, 2009, ISSN: 1144-0546. |
Amine-terminated silicon nanoparticles: synthesis, optical properties and their use in bioimaging Journal Article In: JOURNAL OF MATERIALS CHEMISTRY, 19 (33), pp. 5926–5933, 2009, ISSN: 0959-9428. |
DNA-Templated Homo- and Heterodimerization of Peptide Nucleic Acid Encoded Oligosaccharides that Mimick the Carbohydrate Epitope of HIV Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (41), pp. 7695–7700, 2009, ISSN: 1433-7851. |
Divergent Syntheses of Resorcylic Acid Lactones: L-783277, LL-Z1640-2, and Hypothemycin Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (43), pp. 11490–11497, 2009, ISSN: 0947-6539. |
Synthesis of a Resorcylic Acid Lactone (RAL) Library Using Fluorous-Mixture Synthesis and Profile of its Selectivity Against a Panel of Kinases Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (43), pp. 11498–11506, 2009, ISSN: 0947-6539. |
A Rapidly Shuttling Copper-Complexed [2]Rotaxane with Three Different Chelating Groups in Its Axis Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (45), pp. 8532–8535, 2009, ISSN: 1433-7851. |
Copper-Complexed Pirouetting [2]pseudorotaxanes with Sulfur-Containing End-Groups Attached to the Thread: Synthesis, Electrochemical Studies, and Deposition on Gold Electrodes Journal Article In: AUSTRALIAN JOURNAL OF CHEMISTRY, 62 (10), pp. 1231–1237, 2009, ISSN: 0004-9425. |
Quantitative formation of [4]pseudorotaxanes from two rods and two bis-macrocycles incorporating porphyrinic plates between the rings Journal Article In: CHEMICAL COMMUNICATIONS, (13), pp. 1706–1708, 2009, ISSN: 1359-7345. |
Design and synthesis of porphyrin-containing catenanes and rotaxanes Journal Article In: CHEMICAL SOCIETY REVIEWS, 38 (2), pp. 422–442, 2009, ISSN: 0306-0012. |
Electrochemically Driven Sequential Machines: An Implementation of Copper Rotaxanes Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (6), pp. 1310–1313, 2009, ISSN: 0947-6539. |
A Fast-Moving Copper-Based Molecular Shuttle: Synthesis and Dynamic Properties Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 15 (16), pp. 4124–4134, 2009, ISSN: 0947-6539. |
Macrocycle-Based Liquid Crystals: A Study of Topological Effects on Mesomorphism Journal Article In: MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 509 , pp. 907–914, 2009, ISSN: 1542-1406. |
[3]Rotaxanes and [3]pseudorotaxanes with a rigid two-bidentate chelate axle threaded through two coordinating rings Journal Article In: NEW JOURNAL OF CHEMISTRY, 33 (10), pp. 2148–2154, 2009, ISSN: 1144-0546. |
2008 |
Kinesin's cover-neck bundle folds forward to generate force Journal Article In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 105 (49), pp. 19247–19252, 2008, ISSN: 0027-8424. |
Interrogation, Recognition, and Repair of Damaged Bases in DNA Journal Article In: CHEMICAL RESEARCH IN TOXICOLOGY, 21 (12), pp. 2433, 2008, ISSN: 0893-228X. |
Electronic Transport Properties or Ensembles of Perylene-Substituted Poly-isocyanopeptide Arrays Journal Article In: ADVANCED FUNCTIONAL MATERIALS, 18 (24), pp. 3947–3955, 2008, ISSN: 1616-301X. |
Luminescence properties and redox behavior of Ru(II) molecular racks Journal Article In: COORDINATION CHEMISTRY REVIEWS, 252 (23-24, SI), pp. 2480–2492, 2008, ISSN: 0010-8545. |